IRX3 and obesity due to melanocortin 4 receptor deficiency: Furthermore, by defining the genes/pathways regulated by Irx3 and Irx5 in RGL-NSCs as well as their interplays with the Notch, Shh and Fgf pathways should unveil new knowledge about postnatal remodeling of the hypothalamus and provide mechanistic insights in NSC biology and obesity.