In a broad sense, LS research offers a unique opportunity to address the impact of the GHRH-GH-IGF1 endocrine axis on a number of physio-pathological pathways, including growth, obesity, diabetes, and aging, etc. Obesity constitutes the second major adverse effect of LS (after dwarfism). Here, IGF1 is linked to obesity due to melanocortin 4 receptor deficiency.