Lin et al. evaluated COPD as a potential predictive marker in NSCLC patients by stratifying three different subgroups based on PD-L1 expression (PD-L1 < 1%, PD-L1 1–49% and PD-L1 ≥ 50%), failing to find significant differences among these groups [58]. This evidence concerns the gene CD274 and chronic obstructive pulmonary disease.