CD274 and cancer: Targeted therapies blocking the CD274 (PD‐L1)/PDCD1 (PD1) interaction are a promising therapeutic option for various cancer types and already approved for the treatment of, for example, melanoma, non‐small cell lung cancer (NSCLC), renal cell carcinoma (RCC), bladder cancer, and head and neck squamous cell carcinoma (HNSCC).5