Some evidence in support of this presumption was seen in astrocyte cultures where it was shown that HDAC inhibition increased neurotrophic cytokines (Chen et al., 2006) and mitigated changes in Parkinson’s and Alzheimer’s disease (PD and AD; Nuutinen et al., 2010), although no changes were seen in reducing astrocyte activation (Xuan et al., 2012). Here, HDAC9 is linked to Parkinson disease.