Overexpression of Cyp7a1 in transgenic mice liver reduced cholesterol content in the liver and plasma and prevents atherosclerosis (47); transgenic mice were resistant to high-fat diet-induced fatty liver, obesity, and insulin resistance, and kept triglyceride, cholesterol, and bile acid homeostasis (48). This evidence concerns the gene CYP7A1 and obesity due to melanocortin 4 receptor deficiency.