We assessed that the expression of TIGIT on CD226+ NK cells was up-regulated by the cytokines IL-10, and IL-12 + IL-15, but not TGF-β, in HIV-infected individuals, implying that a disturbed cytokine milieu mediates the over-expression of TIGIT to inhibit activation of CD226+ NK cells during HIV infection. Here, IL15 is linked to HIV infectious disease.