The median frequency of CD57+NKG2C+ NK was not significantly higher in the CMV-seronegative HIV-infected group than the CMV-seronegative control group (p = 0.0877), indicating that, under most circumstances, HIV infection alone does not promote significant expansion of CD57+NKG2C+ NK in the absence of HCMV infection (Figure 1). This evidence concerns the gene KLRC2 and HIV infectious disease.