A substantial body of evidence suggests that the dysregulation of histone acetylation contributes to the pathogenesis of neurodegenerative diseases, and targeted restoration of histone acetylation by HDAC inhibitors shows neuroprotective effects on neurodegenerative diseases (Petrij et al., 1995; Dash et al., 2010; Kilgore et al., 2010; Haettig et al., 2011; Ji et al., 2014). Here, HDAC9 is linked to neurodegenerative disease.