The risk of all-grade pneumonitis were obtained from all patients in both experimental arm and control arm, treatment with ICIs targeting PD-1/PD-L1 did significantly increase the risk of any grade pneumonitis compared with controls (fixed effects, RR: 4.70; 95% CI: 2.81–7.85; p < 0.00001). This evidence concerns the gene PDCD1 and pneumonitis.