BDNF and Huntington disease: Huntington’s disease (HD) is an inherited neurodegenerative disorder caused by an abnormal amplification of the CAG repeats in the Huntington gene.400 The increased expression of BDNF, collagen type-I, and fibronectin in the brain after the transplantation of BM-MSCs into HD rats suggests that MSCs may treat HD through paracrine effects rather than neurological replacement.401 Overall, promising results have been obtained from preclinical studies regarding the therapeutic potential of MSCs in neurodegenerative diseases (Fig. 6).