A group of SNPs from two LD regions in the chr15q24.1 region (CYP1A1 and CYP1A2) showed a protective effect on lung cancer risk among never smokers and a suggestive risk of lung cancer in ever smokers with a significant genotype-smoking interaction for CYP1A1 rs2606345 and a nominally significant interaction for the two SNPs in CYP1A2. This result was confirmed by the multiple SNP analysis stratified by smoking. This evidence concerns the gene CYP1A1 and lung cancer.