KLRC2 and HIV-1 infection: Nonetheless, it is also the case that the frequency of NKG2C+(CD57+) NK cells is higher in HCMV seropositive donors with HIV-1 infection than in HCMV seropositive donors without HIV-1 infection (102), suggesting either that – as for hantavirus or chikungunya virus – HIV-1 infection drives expansion of the HCMV-induced NKG2C+ population or that HIV-1 infected individuals experience more frequent reactivation of HCMV which then expands the NKG2C+ population.