Amid the modest durability and substantial iRAEs that have limited the clinical utility of conventional CTLA-4 inhibitors with PD-1/PD-L1 inhibitors combinations in SCLC, the advent of PD-1/CTLA-4 bispecific antibodies—exemplified by cadonilimab—offers a mechanistically refined strategy that maintains potent antitumor activity. This evidence concerns the gene PDCD1 and small cell lung carcinoma.