PSEN1 and Alzheimer disease: miR-9 targets a number of proteins involved in AD pathogenesis pathways, including BACE1, PSEN1, Sirtuin-1 (a protein involved in reducing Aβ peptides and anti-aging) and Calcium/Calmodulin Dependent Protein Kinase Kinase 2 (CAMKK2) [[26], [27], [28]].