Cancers with mismatch repair (MMR) deficiency, which invariably contributes to very high mutation rates, have consistently responded to pembrolizumab (PD-L1 blockade) [88]., Additionally, atezolizumab, an engineered humanized immunoglobulin G1 monoclonal antibody for PD-L1, has shown tolerability and durable activity in urothelial cancers with high TMB in proportion to increased levels of PD-L1 expression on immune cells [89]. Here, CD274 is linked to cancer.