Several groups showed that NK cells from AML patients or expanded with IL15 have high levels of GSK3β and that chemical inhibition of GSK3β can improve their antitumor activity through an increase in NFKB signaling molecules (RELA, RELB, c-REL, NFKIBA) [5] However, our data showed that FC21 expansion of NK cells does not increase GSK3β levels, and therefore its deletion did not alter their cytotoxicity, in both short and long-term killing assays we used here. The gene discussed is REL; the disease is acute myeloid leukemia.