CD274 and head and neck squamous cell carcinoma: Current studies in HNSCC suggest that the Combined Positive Score (CPS)—the number of PD-L1 positive cells, including tumor cells, lymphocytes, and macrophages, relative to total tumor cells—is a more effective measure compared to the Tumor Proportion Score (TPS), which only evaluates PD-L1 expression on tumor cells [76–79].