PRF1 and neoplasm: These include: the specific recognition of tumor-associated antigens and the expression of effector molecules by T lymphocytes (type I and II- interferon, perforin, Fas/FasL, tumor necrosis factor (TNF)-related apoptosis-inducing ligand—TRAIL), analogously to a viral infection, paralleled by the expression of recognition molecules such as NKG2D or ligands on tumor cells (induced by DNA damage and stress pathways) (117).