(+)-Benzo[a]pyrene-7,8-dihydrodiol-9,10-epoxide binds to the N2 atom of a guanine nucleobase in DNA,[2][3] distorting the double helix structure[4] by intercalation of the pyrene moiety between base pairs through π-stacking.

[5] The carcinogenic properties of tobacco smoking are attributed in part to this compound binding and inactivating the tumor suppression ability of certain genes, leading to genetic mutations and potentially to cancer.

[11] (+)-Benzo[a]pyrene-7,8-dihydrodiol-9,10-epoxide has been shown to bind to an N2 atom of a guanine nucleobase in DNA,[2][3] distorting the double helix structure[4] by intercalation of the pyrene moiety between base pairs through π-stacking.

The anti-benzo[a]pyrene diol epoxides induce guanine to thymine transversions in related areas of p53, thereby inactivating its tumor suppression ability in certain cells, leading to genetic mutations and potentially to cancer.

Seemingly, CYP1A1 activity in the intestinal mucosa prevents major amounts of ingested benzo[a]pyrene to enter portal blood and systemic circulation.