In mice, POMCCre-dependent over-activation of the phosphatidylinositol-3-kinase (PI3K)-Akt-mammalian target of rapamycin (mTOR) pathway causes hyperpolarization of POMC neurons leading to obesity [[10], [11], [12]]. The gene discussed is POMC; the disease is obesity due to melanocortin 4 receptor deficiency.