POMC and obesity due to melanocortin 4 receptor deficiency: 5HT2CR expression solely on POMC neurons ameliorated energy balance phenotypes of 5HT2CR null mice including: hyperphagia, sensitivity to diet-induced obesity, locomotor hyperactivity, insulin resistance, and insensitivity to the anorectic effects of serotonin agonists (Xu et al., 2008, 2010a,b).