A phase III study (KEYNOTE-048) date demonstrated that Pembrolizumab compared to chemotherapy has remarkably improved OS in recurrent/metastatic (R/M) HNSCC patients with PD-L1 combined positive score (CPS) ≥20 and its combinations with chemotherapy was more efficacious compared to chemotherapy in R/M HNSCC patents with PD-L1 CPS ≥1, proposing c [44]. This evidence concerns the gene CD274 and head and neck squamous cell carcinoma.