Therefore, decreased expression of hsa-miR-20a-5p in AD patients increased APP expression and decreased hsa-miR-185-5p and hsa-miR-181c-5p, thereby increasing the expression of its targets, which further upregulates β-secretase and γ-secretase and downregulates α-secretase to increase Aβ generation and plaque formation. Here, APP is linked to Alzheimer disease.