To further explore the PD-1/PD-L1 axis in HNSCC, we evaluated and compared frequencies of PD-1 and PD-L1 immunohistochemical expression in a clinically well characterized cohort of OCSCCs of 80 primary tumors and 28 associated nodal metastasis and determined its prognostic impact. The gene discussed is CD274; the disease is head and neck squamous cell carcinoma.