In SCLC patients, PD‐L1 positivity was independently associated with lower lung cancer‐specific (multivariable HR = 0.11; 95% CI = 0.006–0.52; P = 0.0020) and overall (multivariable HR = 0.19; 95% CI = 0.046–0.55; P = 0.0010) mortality. This evidence concerns the gene CD274 and lung cancer.