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<!-- DFIN ActiveDisclosure(SM) XBRL Schema Document - http://www.dfinsolutions.com/ -->
<!-- Creation Date      : 2021-05-13T03:37:41.9197247+00:00 -->
<!-- Version            : 5.0.1.615 -->
<!-- Package ID         : a9583fa121094479ba079b30441fabc8 -->
<!-- Copyright (c) 2021 Donnelley Financial Solutions, Inc. All Rights Reserved. -->
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  <xsd:element id="nktx_NKCellProductsMember" name="NKCellProductsMember" type="nonnum:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
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</xsd:schema>
