CTLA4 and non-small cell lung carcinoma: Subgroup analyses were performed based on the line of ICIs, the use of ICIs alone or in combination, and the type of ICIs.<h4>Results</h4>A total of 9826 NSCLC patients from 21 randomized controlled trials (RCTs) with 4064 EAs were included, which involved PD-1, PD-L1, and CTLA-4 inhibitors.