MAPT and Alzheimer disease: Alzheimer’s disease (AD) is a neurodegenerative disorder primarily associated with dementia and pathological features such as extensive neuronal and synaptic loss, accumulation of plaques consisting of amyloid β-peptide (Aβ), and intracellular neurofibrillary tangles (NFTs) formed by hyperphosphorylated tau (p-tau) protein (Braak and Braak, 1991).