KIR3DL1 and acute myeloid leukemia: In this regard, Chretien et al. (42) compared the presence of five different stages of NK cell development (CD56high, CD56low/KIR−/CD57−, CD56low/KIR+/CD57−, CD56low/KIR−/CD57+, and CD56low/KIR+/CD57+) in the PB of AML patients and found that one-third of the patients exhibited a significant increase in the proportion of the more mature CD56low/KIR+/CD57+ NK cells at the expenses of more immature CD56high NK cell subset.