Pembrolizumab (Keytruda, Merck & Co, Inc), a T-cell PD-1 inhibitor that prevents the binding of PD-1 to its ligands, programmed cell death ligand 1 and programmed cell death ligand 2, which are frequently overexpressed on cancer cells, is regarded as an efficacious treatment of MCC and SCC and is Food and Drug Administration-approved for the treatment of both malignancies.3 This evidence concerns the gene CD274 and cancer.