Due to the fact that NK cells can express various inhibitory receptors including PD-1, TIM3, Lag3, and TIGIT, and that higher expression of these inhibitory receptors was associated with worse prognosis in AML (66), there is rationale for using inhibitory receptor blockade to bolster NK-mediated immune responses against leukemia. Here, PDCD1 is linked to acute myeloid leukemia.