CD274 and head and neck squamous cell carcinoma: It is important to highlight that, even if the choice of CPS as a scoring method to evaluate the PD-L1 expression seems to strengthen its predictive potential [107], the results of the most recent trials where pembrolizumab was administered to R/M HNSCC patients seem to suggest that anti-PD-L1 immunotherapy should not be restricted only to PD-L1 expressing tumors.