The ubiquitously expressed mutant ataxin-3 interferes with cellular homoeostasis and initiates a cascade of pathogenic events [18], including transcriptional dysregulation, which has been detected in blood samples from MJD mutation carriers [19–23], at very early disease stages and even prior to disease onset [23]. This evidence concerns the gene ATXN3 and Spinocerebellar ataxia type 3.