Although ChAT mRNA expression and protein levels are epigenetically modulated by hyperacetylation of the core promoter region of the ChaT transcript (Aizawa et al., 2012), decreased HDAC2 nuclear levels were found within cholinergic nbM neurons in MCI, but significantly decreased ChAT nbM protein levels were seen only in AD (Mahady et al., 2019). This evidence concerns the gene HDAC2 and Alzheimer disease.