Three SNPs in the chr15q24.1 region (CYP1A1/A2) showed a protective effect for lung cancer among never smokers but a tendency towards increased risk of lung cancer in ever smokers, with a significant genotype-smoking interaction for CYP1A1 rs2606345 (pinteract = 0.005) and a nominally significant genotype-smoking interaction for the two SNPs in CYP1A2. The gene discussed is CYP1A1; the disease is lung carcinoma.