The enhanced functional properties of CMV-induced donor-derived NKG2C+ memory NK cells compared to conventional NK cells are caused by epigenetic remodeling resulting in increased proliferative responses as well as cytokine production (21, 24, 26).Interestingly, expansion of these cells after HSCT is not only associated with protection from CMV reactivation (27), but also trended to be associated with a reduced rate of AML relapse (28). Here, KLRC2 is linked to acute myeloid leukemia.