BCL2 and Alzheimer disease: Moreover, BCL2 was found to be down‐regulated by miR‐34a in a mouse model of Alzheimer's disease, and miR‐34a repression in cell lines resulted in up‐regulation of the BCL2 protein and a decrease in caspase 3 levels.56 Silent information regulator 1 (SIRT1) is a deacetylase that regulates apoptosis induced by oxidative stress and DNA damage by inactivating several molecular targets, including p53.