However, in various neurodegenerative diseases, including Alzheimer’s disease (AD), frontotemporal dementia (FTD) with parkinsonism linked to chromosome 17 (FTDP-17), progressive supranuclear palsy (PSP), corticobasal degeneration (CBD), Pick’s disease (PiD), etc., tau is abnormally phosphorylated, leading to the formation of protein inclusions such as neurofibrillary tangles (NFTs), which are collectively referred to as “tauopathies” (Table 1) [8]. The gene discussed is MAPT; the disease is early-onset autosomal dominant Alzheimer disease.