Our study is a phase II trial on irinotecan in the second‐ or later‐line setting after combined treatment with anti‐PD‐L1 and platinum‐etoposide against ES‐SCLC to evaluate the effect of irinotecan after treatment with anti‐PD‐L1 plus platinum‐etoposide. The gene discussed is CD274; the disease is small cell lung carcinoma.