Receiving programmed cell death-1 (PD-1) or ligand-1 (PD-L1) inhibitors, having squamous cell carcinoma (SCC), and having poorer performance status were independently and significantly associated with increased risk of pneumonitis, with AOR (adjusted odds ratios) of 8.32, 4.10, 2.91, and 1.71, respectively. This evidence concerns the gene CD274 and pneumonitis.