CYP2A6 regulates nicotine metabolism

a minor fraction of variance ... is accounted for by known reduced activity CYP2A6 variants

Smokers with reduced or null activity alleles of CYP2A6 metabolize nicotine more slowly

Reduced and null activity alleles of the CYP2A6 gene ... alter ... nicotine metabolism

Nicotine is largely metabolized to its primary metabolite cotinine by the hepatic enzyme CYP2A6