KLRB1 and HIV-1 infection: To further clarify whether the decreased CD161 expression in HIV-1-infected individuals was really caused by HIV-1 infection and to determine the proportion of CD161+ CD4+ T cells that could be recovered after ART, we followed CD161 expression on CD4+ T cells from 13 subjects at different time points from the beginning of ART to after 1 year of ART.