While it remains unclear exactly how these mice overcome the negative effects of RalA deletion on glucose uptake, GLUT4 mRNA and protein levels in WAT are downregulated in obesity 12,47,48 GLUT1 mRNA and protein levels are increased 49,50, consistent with our RalGAP KO studies in HFD-fed mice that show little glucose uptake into white fat in response to insulin, but higher basal levels 26. Here, SLC2A4 is linked to obesity due to melanocortin 4 receptor deficiency.