HDAC9 and Alzheimer disease: Although dysregulation of histone acetyltransferases (HATs) and deacetylases (HDACs) has been considered fundamental for the onset and/or progression of neurological disorders [94], the differential spatial dysregulation observed in the HDAC SIRT protein family suggests that protein deacetylation-based mechanisms involved in neuronal homeostasis and proteostasis of proteotoxic species differs not only between AD and PD but also between women and men.