Emerging evidence suggests that anti‐PD‐1/PD‐L1 therapy is effective in various malignancies, including SCLC, and PD‐L1 expression in cancer cells is a potential predictive marker of the clinical response to anti‐PD‐1/PD‐L1 therapy 6, 7, 8, 9, 10, 11, 12, 13, 14, 15. This evidence concerns the gene PDCD1 and small cell lung carcinoma.