CYP1A1 and breast carcinoma: With regard to CYP1A1 M2-containing genotypes, Moysich and colleagues [24] reported an OR for breast cancer of 2.9 (95% CI 1.2–7.5) in postmenopausal women with total PCBs between 3.72 and 19.04 ng/g and CYP1A1 M2-containing genotypes compared with women with low PCBs and non-M2-containing genotypes.