This observation diverges from previous studies [42, 43] suggesting that there was no clear difference between PD‐L1 and PD‐1 inhibitors in ES‐SCLC, and one study [42] found that PD‐L1 inhibitors had a tendency to reduce the risk of death in ES‐SCLC patients with BMs compared to PD‐1 inhibitors. Here, CD274 is linked to small cell lung carcinoma.