PDCD1 and neoplasm: T-cell immunoglobulin and ITIM domain (TIGIT) is a coinhibitory receptor that is expressed on NK cells and different types of T cells, including effector and memory T cells and Tregs.408–410 The ligands of TIGIT, CD155 (PVR) and CD112 (PVRL2, nectin-2) are expressed on APCs, T cells, and tumor cells.411,412 In NHL, TIGIT and PD-1 are frequently coexpressed on TILs.