Monoclonal antibodies (mAbs) targeting the programmed death 1 (PD1)/programmed death ligand-1 (PD-L1) pathway have achieved impressive response rates in patients with melanoma, non-small cell lung cancer, and bladder cancer, and PD-L1 has been validated as a predictive biomarker for the outcome of mAb therapy in many studies14–16. The gene discussed is CD274; the disease is melanoma.