found that up-regulation of inhibitory receptors NKG2A on NK cells leads to loss of effective recognition of CML cells by NK cells (197), Meanwhile, the CML cells themselves can secrete a variety of cytokines such as IL-10 and TGF-β, which could inhibit the function and proliferation of NK cells (107). This evidence concerns the gene KLRC1 and chronic myelogenous leukemia, BCR-ABL1 positive.