KCNJ2 and obesity due to melanocortin 4 receptor deficiency: To understand the mechanism of action in obesity reversal, we subjected the mice to metabolic measurements at a time before body weight difference between the two groups reached significance and found that the Kir2.1 mice showed reduced food intake (Figure 4G) but no significant difference in either O2 consumption (Figures S10A and S10B) or locomotion (Figures S10C and S10D).