TIGIT and neoplasm: It is also a cell surface receptor that is highly expressed on endothelial cells, fibroblasts, DCs and tumour cells.48 CD155 is highly expressed on the surface of tumours, binds to TIGIT on the surface of NK and T cells, increases IL-10 secretion, reduces the secretion of pro-inflammatory cytokines, and inhibits the antitumour immune response.