The depletion of CD8+ T cells eliminated the therapeutic efficacy of VV-α-TIGIT, which was accomplished by the reduction of lymphocyte subsets (T, NK, NKT) and IFN-γ secretion, indicating that the activation of CD8+ T cells has an indispensable role in anti-cancer immunity induced by VV-α-TIGIT. This evidence concerns the gene TIGIT and cancer.