The deposition of Aβ, intracellular aggregation of hyperphosphorylated Tau protein, the loss of synapses, neuroinflamamiton and autophagic dysfunction, as well as aging reveal the critical roles in the pathogenesis of AD, which is associated with the dysfunctional regulation of a series of microRNAs (Figure 1). The gene discussed is MAPT; the disease is Alzheimer disease.