RARRES2 and obesity due to melanocortin 4 receptor deficiency: Adipose tissue produces several proteins (adipokines) such as leptin, adiponectin, visfatin, chemerin, and resistin, which have been shown to play an important role in the pathogenesis of insulin resistance, diabetes, obesity, dyslipidaemia, inflammation and atherosclerosis [11], and these adipokines regulate many physiological functions such as energy balance, insulin sensitivity, glucose homeostasis, regulation of food intake, regulation of blood pressure and inflammatory response [12].