Although a significant number of patients with cancer benefit from anti-PD-1 therapy, many fail to have clinical responses.1 To date, the most successful biomarker associated with response to anti-PD-1 therapy is tumor cell expression of programmed death-ligand 1 (PD-L1).2 3 However, more than half of NSCLC patients with high PD-L1 expression (≥50%) do not respond to anti-PD-1 therapy, while 9%–17% of those without PD-L1 expression (<1%) do respond.4–6. The gene discussed is CD274; the disease is non-small cell lung carcinoma.