PVR and neoplasm: 1.TIGIT indirectly impedes T cell function by binding to CD155 on DCs, promoting tolerogenic DCs with decreased production of IL-12 and increased production of IL-10.    2.TIGIT exhibits direct immune cell-intrinsic inhibitory effects.3. TIGIT inhibits NK cell degranulation, cytokine production, and NK cell-mediated cytotoxicity of CD155-expressing tumor cells.4.TIGIT is highly expressed on Tregs and TIGIT+Tregs demonstrated to be superior in suppressing T cells.