APP and Mental deterioration: miRNA-106b (downregulated in the anterior temporal cortex) can influence Aβ metabolism either through direct regulation of APP itself, or via modulating APP trafficking, Aβ clearance and β- and γ-secretase activity through the regulation of the ATP-binding cassette transporter A1 (ABCA1), which is elevated in the hippocampus, correlating with cognitive decline [157].