Consistently, in vitro experiments have suggested that KIR3DL1/HLA-Bw4 genotype combinations have higher educated NK cytotoxic responses than NK cells from Bw6 homozygotes against HLA-downregulated target CML cell lines (K562) [9,108,109,110] or HIV-infected CD4+ T cells that decreased the levels of HLA-A, -B and -C by Nef and Vpu HIV proteins [111,112,113,114] emulating the missing-self NK cytotoxic activity (Figure 3) [4,114,115]. This evidence concerns the gene CD4 and chronic myelogenous leukemia, BCR-ABL1 positive.