CYP2E1, Belonging to the cytochrome P450 family. Cytochrome P450 protein is a monooxygenase that catalyzes many reactions related to drug metabolism as well as the synthesis of cholesterol, steroids, and other lipids. CYP2E1 metabolizes several prec bacteria, drugs, and solvents into reactive metabolites, inactivating many drugs and xenotoxins, and attracting many biologically activated xenobiotic substrates to their hepatotoxic or carcinogenic forms.