1) Mitochondrial ETC protein complexes have been shown to have compromised activity in cell models of SCA2 [151] and SCA3/MJD [155, 156], in various brain regions of SCA1 mouse models [157, 158], and in both patient samples and mouse models of SCA7 [159, 160]. The gene discussed is ATXN1; the disease is Machado-Joseph disease.