Circulating adiponectin levels are reduced in obesity [140,141,142], whereas the expressions of adiponectin receptors are increased, as evidenced by higher mRNA expressions of AdipoR1 in skeletal muscle in obese subjects [147] and AdipoR2 in insulin-resistant subjects [148]. The gene discussed is ADIPOQ; the disease is obesity due to melanocortin 4 receptor deficiency.