Previous results suggest that activation of random subsets of ArcGABA neurons causes massive obesity.18 Given the major role of ArcGABA neurons in mediating leptin action on body weight regulation and the current results showing a profound role of ArcGABA non-LepR neurons in obesity development, Arc LepR and non-LepR neurons represent two subsets of ArcGABA neurons important for body weight regulation. Here, ARC is linked to obesity due to melanocortin 4 receptor deficiency.