One of these enzymes, CYP1A1 (aryl-4 monooxygenase), has been linked to the intestinal detoxification of benzo(a)pyrene depending on TLR2, a host cell membrane receptor triggered by bacterial lipoproteins and other cell wall components; TLR2-deficient mice had reduced ability to clear benzo(a)pyrene and developed colon polyps after dietary supplementation with this compound [101]. The gene discussed is TLR2; the disease is polyp of colon.