We found that the phosphorylated tau level, but not the total tau level, was dramatically lower in cells overexpressing miR-504-3p mimics than in cells in the untreated and NC mimic groups (Fig. 10a, b), indicating that miR-504-3p reduces tau phosphorylation at the CDK5-dependent phosphorylation sites related to AD. This evidence concerns the gene CDK5 and Alzheimer disease.