CD274 and neoplasm: However, only 13–18% of platinum-resistant patients [2] and 19–36% of HNSCC patients receiving pembrolizumab in the first-line setting respond favorably (i.e., complete or partial response) even when the tumor expresses high PD-L1 (PD-L1 combined positive score (CPS) ≥1 and ≥20) [3], suggesting only a small fraction of HNSCC patients benefit from ICB.