In summary, animal models of immune or alcoholic liver injury were previously applied, and different laboratories drew similar conclusions, including that inflammatory cytokines such as IL-1β and TNF-α as well as iNOS are involved in the regulation of CYP2E1; however, inter model differences regarding the contribution of CYP2E1 to metabolism and toxicity in the last decade are not well understood [12]. This evidence concerns the gene CYP2E1 and medical procedure.