CD274 and head and neck squamous cell carcinoma: For example, in a retrospective analysis of patients treated with pembrolizumab, there was no significant difference in response by tumor PD-L1 expression alone (defined as ≥1%), but when combination tumor plus TIL PD-L1 expression was used, PD-L1 positive HNSCC patients had a significantly higher RR, PFS, and OS (73).