CYP2A6 and lung cancer: The analysis, involving 4385 lung cancer cases and 4142 controls, suggested that CYP2A6 polymorphism significantly reduces the risk of lung cancer (pooled OR=0.39; 95% CI: 0.27–0.56), with homogeneity observed across studies (χ2=2.49, p=0.96, I2=0%).