CD274 and head and neck squamous cell carcinoma: Sixty patients with R/M SCCHN (+/− prior treatment) with any detectable PD-L1 expression (≥1%) on tumor cells/stroma and Eastern Cooperative Oncology Group (ECOG) performance status (PS) 0–1 were treated with pembrolizumab monotherapy and received 10 mg/kg bodyweight (BW) every two weeks (q2w).