The expression of PD-L1, the ligand for the T-cell inhibitory receptor PD-1, is often high in HNSCC patients (46–100% of tumors)32 and has been shown to suppress cytotoxic T cells that destroy tumors and also serves as a biomarker (reviewed in ref. 33) predicting a better response to anti-PD-1 therapy. The gene discussed is CD274; the disease is head and neck squamous cell carcinoma.