INS and obesity due to melanocortin 4 receptor deficiency: Each of these rodent models represents different types and severities of pathological features of MetS, i.e., 1/obesity as shown by increased BW, triacylglycerides, free fatty acids, cholesterol and/or liver steatosis, 2/prediabetes or T2DM as shown by increased glucose and insulin levels and glucose intolerance, 3/leptin and/or insulin resistance as shown by disrupted peripheral and central leptin or insulin signaling and 4/hypertension as shown by increased blood pressure.