CYP1A1 and Infertility: DMBA undergoes ovarian biotransformation via CYP1B1 to an intermediate epoxide, which undergoes hydroxylation by EPHX1 to a more potent metabolite DMBA-3,4 diol followed by epoxidation by CYP1A1 or CYP1B1 to the ultimate toxicant DMBA-3,4-diol-1,2-epoxide, that is capable of damaging primordial follicles (Igawa et al. 2009) resulting in oocyte depletion and infertility.