MAPT and red-green color blindness: Aberrant tau accumulation is also a pathological hallmark of other neurodegenerative disorders, collectively known as primary tauopathies, including progressive supranuclear palsy (PSP), corticobasal degeneration (CBD), Pick’s disease (PiD), and frontotemporal dementia with parkinsonisms linked to chromosome 17 (FTDP-17), in which amyloid pathology is not usually observed [23].