MAPT and Alzheimer disease: In Alzheimer’s disease (AD), frontotemporal dementia (FTD), and related neurodegenerative brain diseases, Tau aggregates into insoluble amyloid-like fibrils that accumulate in the neuronal cytoplasm as neurofibrillary tangles (NFTs) and correlate with neurotoxicity, neuronal loss, and cognitive decline in these diseases4,5.