Abnormally hyperphosphorylated microtubule-associated protein tau, the major protein of the intracellular neurofibrillary tangles in Alzheimers disease (AD) brain and related tauopathies [1], is most probably the result of an imbalance of tau kinase and phosphatase activities in the affected neurons.The density of NFTs composed of hyperphosphorylated tau protein in the hippocampus and neocortical areas correlates well with the cognitive impairment in AD [2, 3].Thus, hyperphosphorylation of tau is believed to be pivotal to AD pathogenesis, but the molecular mechanism has not been completely elucidated.