TIGIT and neoplasm: As an IC receptor within the IgSF, TIGIT interacts with ligands such as CD155 (PVR or Nectin-5), CD113 (PVRL3 or Nectin-3), CD112 (PVRL2 or Nectin-2) and PVRL4 (Nectin-4) to suppress T cell activity, facilitating tumour evasion of immune surveillance [54].