Our previous results demonstrate that chronic activation of arcuate GABAergic (ArcGABA) neurons promotes obesity in a redundant manner; i.e., activation of a subset of these neurons is sufficient to induce equivalent body weight gain.18 Since it is known that Arc LepR neurons only represent a subset of Arc neurons,19,20 we investigated the role of non-LepR neurons in body weight regulation. This evidence concerns the gene ARC and obesity due to melanocortin 4 receptor deficiency.