Taioli et al. conducted a pooled analysis (3,688 cases and 3,874 controls) and found the OR for lung cancer was 0.88 (95% CI 0.80–0.97) for the A/G variant of MPO 463G>A polymorphism, and 0.71 (95% CI 0.57–0.88) for the A/A variant after adjusting for smoking, age, gender, and ethnicity [35]. This evidence concerns the gene MPO and lung cancer.