ATXN3 and Spinocerebellar ataxia type 3: In spinocerebellar ataxia type 3 (SCA3), in which abnormal CAG repeats are localized in the coding region of a gene encoding ataxin-3, there is upregulation of matrix metalloproteinase 2 (MMP-2), interleukin-1 and the cytokine stromal cell-derived factor 1alpha (SDF1alpha) due to astroglial and microglial inflammation [100], causing abnormalities in the Purkinje cell.