Immune checkpoint inhibitors (ICIs) have revolutionized the therapeutic landscape of several malignancies, including small-cell lung cancer (SCLC), and programmed death-ligand 1 (PD-L1) inhibition (with either atezolizumab or durvalumab) - added to etoposide and either carboplatin or cisplatin chemotherapy - has become the standard first-line treatment for extensive-stage (ES)-SCLC (1, 2). The gene discussed is CD274; the disease is small cell lung carcinoma.