ATXN3 and Spinocerebellar ataxia type 3: An abnormal accumulation of misfolded expanded ATX3, along with molecular chaperones, transcription factors or co-activators, and the components of the proteasome, forms highly ubiquitinated neuronal inclusions, which constitute a pathological hallmark of MJD/SCA3, as in other polyglutamine diseases (5,6).