CXCL12 and Huntington disease: Such angiogenesis should result in chemokines such as SDF-1 [56], angiogenic molecules, such as vascular endothelial growth factor (VEGF) [57], and neurotrophic factors, such as fibroblast growth factor (FGF), ciliary neurotrophic factor (CNTF), and nerve growth factor (NGF) [14] having more chance to reach the injured region through the newly formed blood vessels, thus further benefiting the damaged neurons, and finally causing the functional improvement seen in our HD mouse models.