TIMP3 and cerebellar ataxia: Notably, some of these differentially expressed genes play important roles in the human brain such as Ataxin1 (ATXN1), which is mutated in spinocerebellar ataxia (50), and tissue inhibitor of metalloproteinases 3 (TIMP3), which is an inhibitor of the matrix metalloproteinases that have been linked to neurodegenerative disorders (Fig. 6F) (51).