CD274 and head and neck squamous cell carcinoma: The prognostic role of PD-L1 in HNSCC varies according to different studies, with some studies reporting that it may predict improved survival, and others reporting the opposite (19), while high PD-L1 expression on >5% intra-tumoral immune cells together with high CD8+ TILs infiltration were shown to be significantly associated with better prognosis in HPV(+)OPSCC (10).