MAPT and Alzheimer disease: Several brain-enriched miRNAs have now been identified that are pathologically altered in AD brains through different signaling pathways, for example, miR-29/β-site amyloid protein precursor (APP) cleaving enzyme 1 (BACE1), miR-132/tau, and miR-124/tyrosine–protein phosphatase nonreceptor type 1 (miR-124/tyrosine-PTPN1) (17–19).