Smoking was identified as a predominant risk factor and CYP1A1*2A polymorphism significantly associated with increased lung cancer risk (OR = 1.69; 95% CI = 1.11–2.59, p = 0.01), whereas CYP1A1*2A and *2C and Ile105Val imparted increased risk in non-smokers only [41]. The gene discussed is CYP1A1; the disease is lung cancer.