MAPT and Alzheimer disease: Moreover, miRNA levels are related to the expression and hyperphosphorylation of tau in the brain [52–54] and are involved in other AD-associated mechanisms, such as aberrant mitochondrial function [55–57], autophagy [58, 59], mitophagy [60, 61], neurotransmitter release and clearance [62, 63], and synaptic plasticity [64].