CD226 and neoplasm: CD112 (Nectin-2, PVRL2) and CD155 (Necl5, PVR) bind CD226 (DNAM-1), which potentiates in vitro the cytotoxicity of NK cells against a wide range of tumor cells (28, 29); CD58 (LFA-3) binds CD2 and its co-engagement with ICAM-1 increases NK response (30).