ATXN3 and Ataxia: MSCs derived from both animals and humans have been shown to secrete various well-known neurotrophic factors, leading to neurogenesis, cell differentiation, angiogenesis, reduction in free radical toxicity, inhibition of apoptosis, formation of glial scars, and neuronal and glial cell survival, thereby inducing neuroprotection and motor improvement in clinical trials with ataxia patients and preclinical ataxia models, such as SCA1-Tg, C57BL/6J-SCA2-Tg, and SCA3-MJD (Tg-ATXN3-Q69 MJD) [16,17,18,22,23,40,41,44,45,46].