Currently, immuno-oncological approaches exploit the antitumor effects of immune checkpoint inhibitors (ICI) targeting programmed cell death protein 1 (PD-1) and its ligand PD-L1 or cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) for HNSCC patients. The gene discussed is CTLA4; the disease is head and neck squamous cell carcinoma.