In unconditional logistic regression analysis, we found that women with at least one CYP1A1 variant Val allele (Ile/Val + Val/Val) had a significantly increased risk of BC (adjusting for age + cotinine) compared to women with the common homozygous Ile/Ile genotype as reference (adjusted OR: 4.35; 95% CI: 1.08-17.4; p = 0.038) (Table 2). This evidence concerns the gene CYP1A1 and breast cancer.