ICI combination was associated with significantly increased odds of pneumonitis compared with conventional therapy (OR 11.66, 95% CrI 5.71 to 26.25), anti-CTLA-4 plus conventional therapy (OR 8.91, 95% CrI 2.11 to 38.68), anti-PD-1/PD-L1 plus conventional therapy (OR 4.01, 95% CrI 1.71 to 9.93), and anti-PD-1/anti-PD-L1 (OR 2.44, 95% CrI 1.29 to 4.71). This evidence concerns the gene CTLA4 and pneumonitis.