endoplasmic reticulum membrane
Cytochrome P450 2A13 is able to oxidise aflatoxin M1 (AFM1) to the reactive aflatoxin M1 epoxide (AFM1E) (He et al. 2006). AFM1E is less carcinogenic or mutagenic than aflatoxin B1-exo-8,9-epoxide (AFBO), but is equally toxic. AFM1E would usually be detoxified by conjugation with glutathione, eventually excreted in urine as a mercapturic acid (not shown here).