CD274 and cancer: Antibodies targeting the inhibitory checkpoint proteins CTLA-4, PD-1, or the PD-1 ligand PDL-1, have been approved for treatment of a variety of cancers, including melanoma, non-small-cell lung cancer, head and neck cancer, bladder cancer, renal cell carcinoma, hepatocellular carcinoma, and several other tumor types, and have resulted in marked and durable responses [100].