INS and obesity due to melanocortin 4 receptor deficiency: The accumulation of visceral fat, a typical symptom of obesity, leads to the production of adipokines such as leptin (8), lipocalin (9), C1q tumor necrosis factor-related protein 9 (10), chemerin (11), and retinol-binding protein 4 (12), which are involved in a variety of metabolic processes such as glucose uptake, insulin signaling, and fatty acid oxidation, and are highly correlated with T2DM and cardiovascular and microvascular complications are highly relevant (13, 14).