In fact, these modules contained genes known to participate in brain development, but not functionally characterized with regard to obesity, such as Hmgcr (95), Klf7 (96), and Lmo1 (97, 98), as well as genes whose role in both development and obesity have been functionally characterized, such as Sim1 (78–87), Creb1 (99, 100), Nrp2 (14), and Phip (22, 23, 101, 102). Here, CREB1 is linked to obesity due to melanocortin 4 receptor deficiency.