NKG2C+ NK cells that expand after CMV infection have been shown to express low levels of NKG2A and p75, but high levels of KIR.18,19,21,24 Indeed, significantly more NKG2C+ NK cells in CMV positive CLL patients have this typical “CMV-specific” NKG2A-KIR+p75-NKG2C+ phenotype (Fig. 1E). This evidence concerns the gene KLRC2 and B-cell chronic lymphocytic leukemia.