Therefore, a number of antibodies against PD-1 and PD-L1 are developed by multiple pharmaceutical companies and are approved in clinical trials for melanoma, non-small cell lung cancer, head and neck squamous cell carcinomas, classical Hodgkin lymphoma and Merkel cell carcinoma by the U.S. Food and Drug Administration (FDA) (4). This evidence concerns the gene CD274 and head and neck squamous cell carcinoma.