CD274 and cancer: Currently, treatments targeting the PD-L1–PD-1 axis have been evaluated in more than 1000 clinical trials and have already been approved for some cancers, including melanoma, renal cell carcinoma, Hodgkin’s lymphoma, squamous cell carcinoma of the head and neck, bladder cancer, non-small cell lung cancer Merkel cell carcinoma, and unstable solid tumours (tall microsatellite or mating deficient solid tumours) [200].