Several promising biomarkers, including programmed cell death ligand-1 (PD-L1), blood tumor mutational burden (bTMB) via circulating tumor DNA, and neutrophil-to-lymphocyte ratio (NLR), were identified in the EAGLE study (NCT02369874) of durvalumab with or without tremelimumab versus chemotherapy in patients with R/M HNSCC who progressed following definitive therapy [9, 10]. Here, CD274 is linked to head and neck squamous cell carcinoma.