Entity Address, City or Town Entity Address, City or Town Entity Ex Transition Period Entity Ex Transition Period Fair Value Disclosures [Abstract] Earnings Per Share [Abstract] Increase in share limit as percentage of outstanding shares of common stock on last trading day in prior year. Increase In Share Limit As Percentage Of Outstanding Shares Of Common Stock On Last Trading Day In Prior Year Increase in share limit as percentage of outstanding shares of common stock on last trading day in prior year Fair Value, Inputs, Level 1 [Member] Quoted Prices in Active Markets for Identical Assets (Level 1) Number of non exclusive rights to gene editing targets licenses received. Number Of Non Exclusive Rights To Gene Editing Targets licenses received Number of non-exclusive rights to gene editing targets licenses received Issuance of common stock upon secondary offering, net of issuance costs Stock Issued During Period, Value, New Issues Net Cash Provided by (Used in) Financing Activities [Abstract] Cash flows from financing activities Amendment Flag Amendment Flag Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Authorized Number of common stock authorized for issuance Subsequent Event Type [Domain] Subsequent Event Type Operating Lease, Right-of-Use Asset Operating lease right-of-use assets Receivable under research cost sharing provision. Receivable Under Research Cost Sharing Provision Receivable under research cost sharing provision Document Quarterly Report Document Quarterly Report Lessee, Operating Lease, Liability, Undiscounted Excess Amount Less imputed interest Earnings Per Share, Policy [Policy Text Block] Net Loss Per Share Cash and Cash Equivalents [Domain] Cash and Cash Equivalents Weighted average number of shares unvested common stock issued upon early exercise of common stock options. Weighted Average Number Of Shares Unvested Common Stock Issued Upon Early Exercise Of Common Stock Options Less: weighted average unvested common stock issued upon early exercise of common stock options Less: weighted average unvested common stock issued upon early exercise of common stock options Statement [Table] Statement [Table] Operating Lease, Liability, Noncurrent Operating lease liabilities, net of current portion Change in Accounting Principle, Accounting Standards Update, Immaterial Effect [true false] Change in Accounting Principle, Accounting Standards Update, Immaterial Effect [true false] Operating Lease, Payments Cash paid for operating leases Number of Operating Segments Number of operating segments Common Stock, Capital Shares Reserved for Future Issuance Number of common stock available for issuance Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Weighted-average grant date fair value per share, outstanding beginning balance Weighted-average grant date fair value per share, outstanding ending balance Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Weighted-average grant date fair value per share, Vested Amounts owed under agreement. Amounts Owed Under Agreement Amounts owed under the agreement Accounting Standards Update 2019-12 [Member] ASU 2019-12 Product and Service [Axis] Product and Service Employee Stock [Member] 2020 Employee Stock Purchase Plan Employee-related Liabilities, Current Accrued compensation Employee-related Liabilities, Current, Total Lessee, Operating Leases [Text Block] Leases Operating Lease, Weighted Average Remaining Lease Term Weighted-average remaining lease term Liabilities and Equity Total liabilities and stockholders’ equity Plan Name [Domain] Plan Name Weighted Average Number of Shares Outstanding, Diluted [Abstract] Denominator: Change in Accounting Principle, Accounting Standards Update, Adopted [true false] Change in Accounting Principle, Accounting Standards Update, Adopted [true false] Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Income Statement [Abstract] Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Organization and Description of Business Sale of Stock [Domain] Sale of Stock Liabilities, Current Total current liabilities Lessee, Operating Lease, Liability, to be Paid, Year Three 2025 Cash cash equivalents restricted cash and short term investments. 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Research Equipment [Member] Research Equipment Entity Small Business Entity Small Business Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents Total cash, cash equivalents and restricted cash Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Beginning Balance Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Ending Balance Collaborative Arrangement and Arrangement Other than Collaborative [Axis] Collaborative Arrangement and Arrangement Other than Collaborative Investments [Domain] Investments Assets, Current Total current assets Property, Plant and Equipment [Line Items] Property Plant And Equipment [Line Items] 2022 (remaining six months) Lessee, Operating Lease, Liability, to be Paid, Remainder of Fiscal Year 2021 (remaining three months) Weighted average shares used to compute net loss per share, basic Weighted Average Number of Shares Outstanding, Basic Weighted Average Number of Shares Outstanding, Basic, Total City Area Code City Area Code Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Forfeitures in Period Number of shares, forfeited Schedule of prepaid expenses and other current assets. Schedule Of Prepaid Expenses And Other Current Assets Table [Text Block] Schedule of Prepaid Expenses and Other Current Assets Share-Based Payment Arrangement [Abstract] Liabilities Total liabilities Document Period End Date Document Period End Date Lease Contractual Term [Domain] Lease Contractual Term Restricted Stock [Member] Restricted Stock Construction in Progress [Member] Construction in Progress Letter of credit notice period by financial institution before annual expiration date. Letter Of Credit Notice Period By Financial Institution Before Annual Expiration Date Letter of credit notice period by financial institution before annual expiration date Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Weighted average grant date fair value of stock option Lessee, Operating Lease, Renewal Term Renewal term Debt Securities, Available-for-Sale, Amortized Cost Available for sale securities, Amortized Cost Statistical Measurement [Axis] Statistical Measurement Other Assets, Current Other current assets Subsequent Event [Line Items] Assets Total assets Net loss per share, diluted Earnings Per Share, Diluted Earnings Per Share, Diluted, Total Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block] Summarizes the Outstanding Potentially Dilutive Securities Excluded in Calculation of Diluted Net Loss Per Share Entity Address, Postal Zip Code Entity Address, Postal Zip Code Increase decrease In operating lease right-of-use assets. Increase Decrease In Operating lease right-of-use assets Operating lease right-of-use assets Operating lease right-of-use assets Document Fiscal Period Focus Document Fiscal Period Focus Restricted Cash Restricted cash Restricted Cash, Total APIC, Share-Based Payment Arrangement, Increase for Cost Recognition Share-based compensation expense APIC, Share-based Payment Arrangement, Increase for Cost Recognition, Total Lease expiration month and year. Lease Expiration Month And Year Lease expiration month and year Operating Lease, Liability Total lease liability Total operating lease liabilities Net Cash Provided by (Used in) Financing Activities Net cash provided by financing activities Short-Term Debt, Type [Axis] Short-term Debt, Type Statement of Financial Position [Abstract] Entity File Number Entity File Number Scenario [Domain] Statement of Cash Flows [Abstract] Balance Sheet Related Disclosures [Abstract] Expected base rent over the lease term. Expected Base Rent Over Lease Term Expects to pay base rent over the lease term Statistical Measurement [Domain] Statistical Measurement Statement of Stockholders' Equity [Abstract] Sale of Stock [Axis] Sale of Stock Share-Based Compensation Arrangement by Share-Based Payment Award, Purchase Price of Common Stock, Percent Commons stock purchase price as percentage of fair value Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract] Comprehensive loss: Fair Value, by Balance Sheet Grouping [Table Text Block] Summary of Fair Value of Financial Instrument Subsequent Events [Abstract] Fair Value Disclosures [Text Block] Fair Value of Financial Instruments Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term Weighted-average remaining contractual term (in years), exercisable Proceeds from Stock Options Exercised Proceeds from stock option exercises Proceeds from Issuance of Common Stock Net proceeds from public offering Accounting policies. Accounting Policies [Line Items] Accounting Policies [Line Items] Amendment of Lease Agreements Amendment Of Lease Agreements [Member] Amendment of lease agreements. Property, Plant and Equipment [Table Text Block] Schedule of Property and Equipment, Net Antidilutive Securities [Axis] Antidilutive Securities Lease expiration year. Lease Expiration Year Lease expiration year Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] Corporate office and laboratory space. Corporate Office And Laboratory Space [Member] Corporate Office and Laboratory Space Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax Available for sale securities, Unrealized Gains Lessee, Lease, Description [Line Items] Lessee Lease Description [Line Items] Supplemental Balance Sheet Disclosures [Text Block] Balance Sheet Components Subsequent Events [Text Block] Subsequent Events Collaborative Arrangement and Arrangement Other than Collaborative [Line Items] Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items] Weighted average shares used to compute net loss per share, diluted Weighted Average Number of Shares Outstanding, Diluted Weighted Average Number of Shares Outstanding, Diluted, Total Corporate Debt Securities [Member] Corporate Debt Securities General and Administrative Expense [Member] General and Administrative Research and Development Arrangement, Contract to Perform for Others, Type [Domain] Research and Development Arrangement, Contract to Perform for Others, Type Commercial Paper [Member] Commercial Paper Current Fiscal Year End Date Current Fiscal Year End Date Investment Type [Axis] Investment Type Financial Instruments [Domain] Financial Instruments Accounting policies. Accounting Policies [Table] Accounting Policies [Table] Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Including Disposal Group and Discontinued Operations Cash, cash equivalents, and restricted cash end of period Cash, cash equivalents, and restricted cash beginning of period Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Including Disposal Group and Discontinued Operations, Total Other Assets, Noncurrent Other long-term assets Other Assets, Noncurrent, Total Entity Address, Address Line One Entity Address, Address Line One Interest Receivable, Current Accrued interest receivable Supplemental disclosures of non-cash investing and financing activities: Supplemental Cash Flow Information [Abstract] Restricted Cash, Noncurrent Restricted cash Income Tax Expense (Benefit) Provision for income taxes Income Tax Expense (Benefit), Total Increase (Decrease) in Operating Lease Liability Operating lease liabilities Operating lease liabilities Income Tax Disclosure [Text Block] Income Taxes Payments to Acquire Property, Plant, and Equipment Purchases of property and equipment Payments to Acquire Property, Plant, and Equipment, Total Income Tax Disclosure [Abstract] Change in Accounting Principle, Accounting Standards Update, Adoption Date Change in Accounting Principle, Accounting Standards Update, Adoption Date Issuance of common stock upon secondary offering, net of issuance costs, Shares Issuance of common stock upon initial public offering, net of issuance costs, Shares Common stock shares issued and sold Assets, Fair Value Disclosure [Abstract] Assets: Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV NK cell products. N K Cell Products [Member] NK Cell Products Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price Weighted-average exercise price, forfeited Operating Income (Loss) Loss from operations Share-Based Compensation Arrangement by Share-Based Payment Award, Shares Issued in Period Shares issued Lessee, Operating Lease, Option to Extend Lessee option to extend description Weighted Average Number of Shares Issued, Basic Weighted average common shares outstanding Additional Paid in Capital, Common Stock Additional paid-in capital Additional Paid in Capital, Common Stock, Beginning Balance Additional Paid in Capital, Common Stock, Ending Balance Payments made under collaborative arrangement. Payments Made Under Collaborative Arrangement Amount paid under the agreement Scenario [Axis] Collaborative Arrangement and Arrangement Other than Collaborative [Table] Schedule Of Collaborative Arrangements And Noncollaborative Arrangement Transactions [Table] Entity Filer Category Entity Filer Category Money Market Funds, at Carrying Value Money market funds Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Other comprehensive gain (loss) Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent, Total Operating Expenses Total operating expenses Entity Current Reporting Status Entity Current Reporting Status Schedule of Accounts Payable and Accrued Liabilities [Table Text Block] Schedule of Accrued Other Current Liabilities Two thousand twenty performance incentive plan. Two Thousand Twenty Performance Incentive Plan [Member] 2020 Plan Reserved for Future Equity Award Grants Debt Securities, Available-for-Sale, Current Short-term investments, available-for-sale Debt Securities, Available-for-sale, Current, Total Stockholders' Equity Attributable to Parent Ending Balance Beginning Balance Total stockholders’ equity Investment Income, Net Interest income Investment Income, Net, Total Debt Securities, Available-for-Sale, Realized Gain (Loss) Realized gain or loss on available-for-sale securities Debt Securities, Available-for-sale, Realized Gain (Loss), Total AOCI Attributable to Parent [Member] Accumulated Other Comprehensive Income (Loss) Short-Term Investments [Member] Short-term investments Acquisitions of property and equipment Noncash or Part Noncash Acquisition, Fixed Assets Acquired Debt Securities, Available-for-Sale, Term Available-for-sale securities, Maturity (in years) Entity Tax Identification Number Entity Tax Identification Number Income Statement Location [Axis] Income Statement Location Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeited in Period Number of shares, forfeited Number of shares, forfeited Common Stock, Value, Issued Common stock Common Stock, Value, Issued, Total Common Stock, Value, Issued, Beginning Balance Common Stock, Value, Issued, Ending Balance Retained Earnings (Accumulated Deficit) Accumulated deficit Accumulated deficit Retained Earnings (Accumulated Deficit), Total Retained Earnings (Accumulated Deficit), Beginning Balance Retained Earnings (Accumulated Deficit), Ending Balance Equity Components [Axis] Accumulated Other Comprehensive (Income) Loss Common stock options. Common Stock Options [Member] Common Stock Options Accounting Standards Update [Domain] Accounting Standards Update Prepaid Expense, Current Prepaid expenses Prepaid Expense, Current, Total Current corporate offices and laboratory space. Current Corporate Offices And Laboratory Space [Member] Current Corporate Offices and Laboratory Space Leases [Abstract] Payments to Acquire Short-Term Investments Purchases of short-term investments Entity Emerging Growth Company Entity Emerging Growth Company Operating Expenses [Abstract] Operating expenses Schedule of Stock by Class [Table] Schedule Of Stock By Class [Table] Letter of Credit [Member] Letter of Credit Depreciation, Depletion and Amortization, Nonproduction Depreciation and amortization Depreciation, Depletion and Amortization, Nonproduction, Total Document Transition Report Document Transition Report Maximum monthly base rent after increase on annual basis. Maximum Monthly Base Rent After Increase on Annual Basis Maximum monthly base rent after increase on annual basis Assets, Fair Value Disclosure Total Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Weighted-average grant date fair value per share, granted Nonoperating Income (Expense) Total other income (expense), net Depreciation, Depletion and Amortization Depreciation and amortization expense Depreciation, Depletion and Amortization, Total Initial lease agreement. Initial Lease Agreement [Member] Initial Lease Agreement Sale of Stock, Price Per Share Stock public offering price Collaborative Arrangement Disclosure [Text Block] CRISPR Collaboration Agreement Commitments and Contingencies Disclosure [Text Block] Commitments and Contingencies Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Weighted-average exercise price, exercised Accumulated Other Comprehensive Income (Loss), Net of Tax Accumulated other comprehensive income (loss) Accumulated Other Comprehensive Income (Loss), Net of Tax, Total Accumulated other comprehensive loss Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Table] Accounts Payable and Other Accrued Liabilities, Current Other accrued and current liabilities Stock issued during period value vesting of shares of common stock subject to repurchase. Stock Issued During Period Value Vesting Of Shares Of Common Stock Subject To Repurchase Vesting of shares of common stock subject to repurchase Net Income (Loss) Attributable to Parent Net loss Net loss Operating Lease, Liability, Current Operating lease liabilities, current portion Additional Paid-in Capital [Member] Additional Paid-In Capital Collaborative Arrangement and Arrangement Other than Collaborative [Domain] Collaborative Arrangement and Arrangement Other than Collaborative Entity Registrant Name Entity Registrant Name Cash and Cash Equivalents, at Carrying Value Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value, Total Cash and Cash Equivalents, at Carrying Value, Beginning Balance Cash and Cash Equivalents, at Carrying Value, Ending Balance Stock Repurchase Program, Number of Shares Authorized to be Repurchased Shares subject to repurchase Earnings Per Share [Text Block] Net Loss Per Share US Government Agencies Debt Securities [Member] U.S. Government Securities Lessee, Lease, Description [Table] Lessee Lease Description [Table] Share-Based Payment Arrangement, Noncash Expense Share-based compensation expense Share-based Payment Arrangement, Noncash Expense, Total Property, Plant and Equipment, Net Property and equipment, net Total property and equipment, net Property, Plant and Equipment, Net, Beginning Balance Property, Plant and Equipment, Net, Ending Balance Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term Weighted-average remaining contractual term (in years), vested and expected to vest Award Type [Domain] Award Type Statement [Line Items] Statement [Line Items] Operating Lease, Expense Rent expense Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price Weighted-average exercise price, vested and expected to vest Title of 12(b) Security Title of 12(b) Security Additional tenant improvement allowances Additional Tenant Improvement Allowances Additional tenant improvement allowances. Common Stock [Member] Common Stock Net Cash Provided by (Used in) Operating Activities [Abstract] Cash flows from operating activities Equity Component [Domain] Equity Component Entity Address, State or Province Entity Address, State or Province Lessee, Operating Lease, Liability, to be Paid, Year Four 2026 Net increase (decrease) in cash and cash equivalents Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Document Type Document Type US Government Corporations and Agencies Securities [Member] U.S. Government Securities Entity Shell Company Entity Shell Company Share-Based Payment Arrangement, Expense Share-based compensation expense Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] Fair Value, Recurring and Nonrecurring [Table] Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Table] Loss Contingencies [Line Items] Loss Contingencies [Line Items] Security Exchange Name Security Exchange Name Class of Stock [Line Items] Class Of Stock [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] Significant Accounting Policies [Text Block] Basis of Presentation and Significant Accounting Policies Net Cash Provided by (Used in) Operating Activities Net cash used in operating activities Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition Unrecognized compensation cost, expected to be recognized over weighted average remaining service period Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term Weighted-average remaining contractual term (in years), outstanding balance Collaboration agreement. Collaboration Agreement [Abstract] Commitments and Contingencies Disclosure [Abstract] Restricted Stock Units (RSUs) [Member] Restricted Stock Units Restricted Stock Unit Activity Lessee, Operating Lease, Liability, Maturity [Table Text Block] Schedule of Maturities of Operating Lease Liabilities Share-Based Payment Arrangement, Restricted Stock Unit, Activity [Table Text Block] Summary of Restricted Stock Unit Activity Share-Based Payment Arrangement, Option, Activity [Table Text Block] Summary of Stock Option Activity New Accounting Pronouncements, Policy [Policy Text Block] Recent Accounting Pronouncements Accretion (Amortization) of Discounts and Premiums, Investments Accretion and amortization of premiums and discounts on investments, net Over-Allotment Option [Member] Underwriters Option to Purchase Additional Shares Fair Value, Inputs, Level 2 [Member] Significant Other Observable Inputs (Level 2) Debt Securities, Available-for-Sale Available for sale securities,Estimated Fair Value Debt Securities, Available-for-sale, Total Net Cash Provided by (Used in) Investing Activities [Abstract] Cash flows from investing activities Computers and software. Computers And Software [Member] Computers and Software Stock issued during period shares vesting of shares of common stock subject to repurchase. Stock Issued During Period Shares Vesting Of Shares Of Common Stock Subject To Repurchase Vesting of shares of common stock subject to repurchase, Shares Commitments and Contingencies Commitments and contingencies (Note 7) Minimum [Member] Minimum [Member] Minimum Tenant improvement receivable. Tenant improvement receivable Share based compensation arrangement by share based payment award offering period. Share Based Compensation Arrangement By Share Based Payment Award Offering Period Offering period Operating Lease, Liability [Abstract] Operating lease liabilities: Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Weighted Average Exercise Price Weighted-average exercise price, exercisable Accounting Standards Update [Axis] Accounting Standards Update Accrued Liabilities, Current Accrued and other current liabilities Accrued Liabilities, Current, Total Stockholders' Equity Attributable to Parent [Abstract] Stockholders’ equity Entity Address, Address Line Two Entity Address, Address Line Two Cash and Cash Equivalents [Axis] Cash and Cash Equivalents Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Weighted-average grant date fair value per share, Forfeited Award Type [Axis] Award Type Subsequent Event [Member] Subsequent Event Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount Unrecognized compensation cost Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total Loss Contingencies [Table] Loss Contingencies [Table] Other income (expense), net Other Nonoperating Income (Expense) Other Nonoperating Income (Expense), Total Potential future payments based on achievement of milestones. Potential Future Payments Based On Achievement Of Milestones Potential future payments Nonoperating Income (Expense) [Abstract] Other income (expense), net: Research and Development Expense Research and development Research and Development Expense, Total Lessee, Operating Lease, Liability, to be Paid Total undiscounted future minimum lease payments Lessee, Operating Lease, Term of Contract Lessee, operating lease, term of contract Monthly base rent. Monthly Base Rent Monthly base rent Cash and Cash Equivalents Cash and Cash Equivalents [Member] Entity Central Index Key Entity Central Index Key Guarantor Obligations, Current Carrying Value Liabilities recorded for agreements Short-Term Investments Total short-term investments Short-term Investments, Total Net Income (Loss) Attributable to Parent [Abstract] Numerator: Accounting Policies [Abstract] Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Less accumulated depreciation and amortization Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment, Total Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment, Beginning Balance Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment, Ending Balance Property, Plant and Equipment [Table] Schedule Of Property Plant And Equipment [Table] Development and regulatory approval milestones. Development and Regulatory Approval Milestones [Member] Development and Regulatory Approval Milestones Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract] Commercial paper Commercial Paper, at Carrying Value Share-Based Payment Arrangement [Text Block] Share-Based Compensation Cash received for tenant improvement allowances to be repaid. Cash Received for Tenant Improvement Allowances to be Repaid Cash received for tenant improvement allowances to be repaid Research collaboration agreement. Research Collaboration Agreement [Member] Research Collaboration Agreement Subsequent Event [Table] General and Administrative Expense General and administrative General and Administrative Expense, Total Organization, Consolidation and Presentation of Financial Statements [Abstract] Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price Weighted-average exercise price, outstanding ending balance Weighted-average exercise price, outstanding beginning balance Research and Development Expense [Member] Research and Development Scenario Forecast Forecast [Member] Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Adjustments to reconcile net loss to net cash used in operating activities: Retained Earnings [Member] Accumulated Deficit Security Deposit Security deposit Money Market Funds [Member] Money Market Funds Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items] Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items] Research and Development Arrangement, Contract to Perform for Others, Type [Axis] Research and Development Arrangement, Contract to Perform for Others, Type Property, Plant and Equipment, Gross Total property and equipment Property, Plant and Equipment, Gross, Total Property, Plant and Equipment, Gross, Beginning Balance Property, Plant and Equipment, Gross, Ending Balance Third amendment. Third Amendment [Member] Third amendment Entity Interactive Data Current Entity Interactive Data Current Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number Number of shares, vested and expected to vest Letters of Credit Outstanding, Amount Letters of credit outstanding amount Number of non exclusive rights to gene editing targets. Number of Non Exclusive Rights to Gene Editing Targets Number of non-exclusive rights to gene editing targets Lessee, Operating Lease, Liability, to be Paid, Year One 2023 Leasehold Improvements [Member] Leasehold Improvements Local Phone Number Local Phone Number Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Computation of Basic and Diluted Net Loss Per Share Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] Share Based Compensation Arrangement By Share Based Payment Award [Line Items] Basis of Accounting, Policy [Policy Text Block] Basis of Presentation Lease Contractual Term [Axis] Lease Contractual Term Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Number Number of shares, exercisable Lessee, Operating Lease, Existence of Option to Extend [true false] Operating lease, existence of option to extend Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross Number of shares, granted Other Liabilities, Noncurrent Other long-term liabilities Other Liabilities, Noncurrent, Total Income Statement Location [Domain] Income Statement Location Proceeds from Sale of Short-Term Investments Maturities of short-term investments Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number Number of shares, outstanding beginning balance Number of shares, outstanding ending balance Shares, Outstanding Ending Balance, Shares Beginning Balance, Shares Increase (Decrease) in Prepaid Expense and Other Assets Prepaid expenses and other assets Increase (Decrease) in Prepaid Expense and Other Assets, Total Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Schedule Of Share Based Compensation Arrangements By Share Based Payment Award [Table] Accrued research and development costs current. Accrued Research And Development Costs Current Accrued research and development costs Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number Number of shares, outstanding ending balance Number of shares, outstanding beginning balance Marketable Securities, Current Marketable securities Marketable Securities, Current, Total Agreement with financial institution. Agreement With Financial Institution [Member] Agreement with Financial Institution Document Fiscal Year Focus Document Fiscal Year Focus Lessee, Operating Lease, Liability, to be Paid, Year Two 2024 Net loss per share, basic Earnings Per Share, Basic Earnings Per Share, Basic, Total Increase (Decrease) in accounts payable and accrued and other liabilities. Increase Decrease In Accounts Payable And Accrued And Other Liabilities Accounts payable and accrued and other liabilities Assets [Abstract] Assets Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents [Abstract] Reconciliation of cash, cash equivalents and restricted cash to the balance sheet: Prepaid Expense and Other Assets, Current Prepaid expenses and other current assets Total prepaid expenses and other current assets Financial Instrument [Axis] Financial Instrument Unvested common stock upon early exercise of common stock options. Unvested Common Stock Upon Early Exercise Of Common Stock Options [Member] Unvested Common Stock Upon Early Exercise of Common Stock Options Long-Lived Tangible Asset [Axis] Long-Lived Tangible Asset Liabilities and Equity [Abstract] Liabilities and stockholders’ equity Antidilutive Securities, Name [Domain] Antidilutive Securities, Name Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Net loss Net Income (Loss), Including Portion Attributable to Noncontrolling Interest, Total Assets, Current [Abstract] Current assets Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV Lessee operating lease liability payments due year five and thereafter. Lessee Operating Lease Liability Payments Due Year Five And Thereafter 2027 and thereafter Increase (Decrease) in Operating Capital [Abstract] Changes in operating assets and liabilities: Lessee, Operating Lease, Remaining Lease Term Lease term Cover [Abstract] Proceeds from secondary offering, net of issuance costs Proceeds From Secondary Offering Net Of Issuance Costs Proceeds from secondary offering net of issuance costs. Product and Service [Domain] Product and Service Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period Number of shares, Vested Liabilities, Current [Abstract] Current liabilities Maximum [Member] Maximum OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment, after Tax Unrealized gain (loss) on short-term investments Net Cash Provided by (Used in) Investing Activities Net cash used in investing activities Furniture and Fixtures [Member] Furniture and Fixtures Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Schedule Of Antidilutive Securities Excluded From Computation Of Earnings Per Share [Table] Issuance of common stock upon exercise of stock option, net of repurchase, Shares Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period Number of shares, exercised Number of shares, exercised Tenant improvements yet to receive from lessor. Tenant Improvements Yet To Receive From Lessor Tenant improvement allowances yet to receive Unusual or infrequent items disclosure. Unusual Or Infrequent Items Disclosure Policy [Text Block] COVID-19 Pandemic Fair Value, Inputs, Level 3 [Member] Significant Unobservable Inputs (Level 3) Share-Based Payment Arrangement, Cost by Plan [Table Text Block] Summary of Share-based Compensation Expense Accounts Payable and Accrued Liabilities, Current Total accrued and other liabilities Use of Estimates, Policy [Policy Text Block] Use of Estimates Total cash equivalents Cash Equivalents, at Carrying Value Accrued property and equipment liabilities current. Accrued Property And Equipment Liabilities Current Accrued property and equipment Issuance of common stock upon exercise of stock option, net of repurchase Stock Issued During Period, Value, Stock Options Exercised Short-Term Debt, Type [Domain] Short-term Debt, Type Trading Symbol Trading Symbol Debt Securities, Available-for-Sale [Table Text Block] Schedule of Short-term Investments Subsequent Event Type [Axis] Subsequent Event Type Operating Lease, Right-of-Use Asset, Amortization Expense Non-cash lease expense Comprehensive Income (Loss), Net of Tax, Attributable to Parent Comprehensive loss Follow on offering of stock. 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