GH1 and Spinocerebellar ataxia type 3: Thus, in this study, the protective effect and possible mechanisms of IGF-1, especially in the regulation of mitochondrial function and autophagy in aggregate protein clearance, the critical factors responsible for IGF-1 benefit in SCA3 treatment, were investigated in SCA3 84Q transgenic mice that were administered a weekly IP injection of IGF-1 for 9 months (the same approach was used for GH intervention in our previous study).