PDCD1 and squamous cell carcinoma: We also performed subgroup analyses for different types of NSCLC (e.g., squamous carcinoma and adenocarcinoma), different immunotherapy drug combinations (e.g., monotherapy, monotherapy combined with chemotherapy, and dual therapy combined with chemotherapy), and different immunotherapy drug types (e.g., PD-1 and PD-L1); however, we did not find any statistical differences (Supplementary Figures S5–S7).