GHRL and obesity due to melanocortin 4 receptor deficiency: In view of the crucial role of GH/IGF-I in mammary gland (patho)physiology, its necessary interdependence with the SST/CORT/ghrelin systems, and the impact that diet-induced obesity (DIO) would likely have in the local expression of these regulatory systems, we hypothesize that a local deregulation of GH/IGF-1 axis (and/or its regulatory systems) may occur in mammary fat pads under obesity conditions and upon the lack of SST or CORT, which could therefore influence the (patho) physiology of the mammary gland.