Programmed cell death protein 1 (PD-1) antibody therapy has been widely used in real-world practice for recurrent and metastatic head and neck squamous cell carcinoma (R/M HNSCC) since the results of the CheckMate-141 trial, which investigated the efficacy and safety of nivolumab in platinum-resistant HNSCC (1). The gene discussed is PDCD1; the disease is head and neck squamous cell carcinoma.