CD274 and neoplasm: The immune checkpoint protein programmed death-1 (PD-1) and its ligand PD-L1 are detected in various solid cancers; PD-1/PD-L1 blockade therapies have greatly improved clinical outcomes in various organ cancers.5 6 MAbs that block or bind to PD-L1 have been approved and are now widely used clinically.7 PD-L1 is found on tumor cell membranes.