MAPT and Alzheimer disease: In addition, GSK3-β is a crucial modulator in AD progression because dysregulated GSK3-βaffects the main features of AD, containing tau phosphorylation, amyloid-β production,and neurogenesis along with synaptic function [39].Of note, miR-21 is widely reported as an important factor in the progression of diseasesvia promoting the PI3K/AKT/GSK3β signaling [40][41].