PDCD1 and small cell lung carcinoma: Apart from adebrelimab plus chemotherapy, atezolizumab plus chemotherapy has also shown positive effects (no liver metastases at baseline vs. liver metastases, OR = 0.59, p = 0.069), suggesting that PD-1/PD-L1 plus chemotherapy could be a potential treatment option for ES-SCLC patients with liver metastasis (Reck et al., 2022).