Given that the expression of several genes involved in adipose tissue homeostasis is known to change in response to metabolic challenges and obesity development, we examined the levels of Mdm2 mRNA in the white adipose tissue (WAT) of diet-induced obese mice (Supplementary Fig. S1c) and genetically obese, ob/ob, mice (Supplementary Fig. S1d). This evidence concerns the gene MDM2 and obesity due to melanocortin 4 receptor deficiency.