Over the past few years, immune‐checkpoint inhibitors (ICIs), including anti‐PD‐1, anti‐PD‐L1, and anti‐CTLA‐4 antibodies, have shown favorable efficacy in both advanced non‐small cell lung cancer (NSCLC) and extensive‐stage small cell lung cancer (SCLC).2, 3. Here, CTLA4 is linked to small cell lung carcinoma.