Thus, we assessed the surface expression of the inhibitory receptors TIGIT, PVRIG, PD-1, and LAG-3, of the ectonucleotidases CD39, CD73, and CD38 and of the activation marker CD69 on NK cells derived from the BM (n = 25, except for PVRIG n = 15) and PB (n = 15) from AML patients in contrast to HDs (n = 12, for PVRIG n = 7). Here, PDCD1 is linked to acute myeloid leukemia.