Multivariate analysis revealed that PD-L1 expression was an independent prognostic factor for OS (HR, 2.317; 95% CI 1.199–4.478; p = 0.012) and PFS (HR, 1.636; 95% CI 0.990–2.703; p = 0.051) in SCLC. The gene discussed is CD274; the disease is small cell lung carcinoma.