MAPT and Alzheimer disease: They hypothesized Aβ aggregates, the main constituent of amyloid plaque, as the causative agent of AD and other abnormalities like hyperphosphorylation of the microtubule-associated protein tau (MAPT/tau), the formation of intracellular neurofibrillary tangles (NFT), cell loss, and dementia follow as subsequent effects of Aβ accumulation (Hardy and Higgins, 1992).