CYP7A1 and obesity due to melanocortin 4 receptor deficiency: Interestingly, overexpression of hepatic CYP7A1 in mice has been shown to protect mice from high-fat diet-induced obesity, insulin resistance, and hepatic steatosis and maintain cholesterol, bile acid, and triglyceride homeostasis [46]; however, metabolic syndrome induced by a high-fat sucrose diet in rats reduced CYP7A1 mRNA expression and protein mass [47].