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  <xs:element id="fhtx_Series1WarrantMember" abstract="true" name="Series1WarrantMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fhtx_Series2WarrantMember" abstract="true" name="Series2WarrantMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fhtx_CollaborationRevenueMember" abstract="true" name="CollaborationRevenueMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
</xs:schema>
