Clinically, a large number of epidemiological studies suggested that the level of serum adiponectin in patients with obesity, type 2 diabetes, and atherosclerotic cardiovascular disease were significantly lower than that in normal subjects (41–43), while the low calorie diets, physical exercise, and bariatric surgery leading to weight loss may result in consistent increases of adiponectin levels (44). The gene discussed is ADIPOQ; the disease is obesity due to melanocortin 4 receptor deficiency.