CD274 and head and neck squamous cell carcinoma: Immune checkpoint blockers (ICBs) targeting programmed cell death protein 1 (PD‐1) have been proven to be an effective first‐line therapy against programmed cell death 1 ligand 1 (PD‐L1; also known as CD274 molecule)‐expressing head and neck squamous cell carcinoma (HNSCC) in recent KEYNOTE‐048 trial.