MAPT and Alzheimer disease: In tauophathies, like Alzheimer’s disease (AD), progressive supranuclear palsy (PSP), frontotemporal dementia and Parkinsonism linked to chromosome 17 (FTDP), corticobasal degeneration, and frontotemporal dementia, tau protein is hyperphosphorylated causing its aggregation, and thereby weakening its microtubule-stabilizing effect.