TIGIT (also called T cell immunoreceptor with Ig and ITIM domains) is an immune receptor present on some T cells and Natural Killer Cells(NK). It is also identified as WUCAM and Vstm3. TIGIT could bind to CD155(PVR) on dendritic cells(DCs), macrophages, etc. with high affinity, and also to CD112(PVRL2) with lower affinity. Research has shown that TIGIT-Fc fusion protein could interact with PVR on dendritic cells and increase its IL-10 secretion level/decrease its IL-12 secretion level under LPS stimulation, and also inhibit T cell activation in vivo. TIGIT's inhibition of NK cytotoxicity can be blocked by antibodies against its interaction with PVR and the activity is directed through its ITIM domain.