CYP2E1 also known as Cytochrome P450 2E1 (abbreviated CYP2E1, EC 1.14.13.n7), is member of the cytochrome P450 mixed-function oxidase system that involved in the metabolism of xenobiotics in the body. While it is involved in the oxidative metabolism of a small range of substrates (mostly small polar molecules), there are many important drug interactions mediated by CYP2E1. Recombinant human CYP2E1, fused to His-tag at N-terminus, was expressed in E.coli.