CD274 and head and neck cancer: The anti-PD-L1 antibodies durvalumab (NCT02207530) and atezolizumab (NCT03073525), and the anti-PD-1 antibodies pembrolizumab (NCT02291055, NCT02255097 and NCT02252042) and nivolumab (NCT02054806, NCT02105636 and NCT02488759) have been tested in clinical trials (phases I and II) for both cervical and head and neck cancers [2, 13].