PDCD1 and colorectal carcinoma: As demonstrated by preliminary data in microsatellite stable colorectal cancer (CRC) patients who typically do not respond to programmed death-ligand 1 (PD-L1)/programmed cell death-1 (PD-1)-based therapy, the combination of monalizumab and durvalumab (an anti-PD-L1 mAb) showed clinical efficacy and safety (81).