Interestingly, the leptin receptor, which regulates key energy homeostatic processes in the hypothalamus and when defective may cause syndromic obesity (Choquet and Meyre, 2011) was only specifically expressed in two out of the 22 BMI GWAS-enriched in the Mouse Nervous System dataset cell types, namely glutamatergic cells from the periaqueductal grey and anterior nucleus of the solitary tract (Figure 6a). This evidence concerns the gene LEPR and obesity due to melanocortin 4 receptor deficiency.