CD274 and neoplasm: Biomarkers indicative of tumor antigenicity, including tumor mutational burden (TMB) and microsatellite instability (MSI), as well as inflammatory biomarkers related to a T‐cell‐inflamed tumor microenvironment, such as programmed death‐ligand 1 (PD‐L1) expression and T‐cell‐activated gene expression signatures, may help characterize patient subpopulations who can benefit from these therapies.2