MAPT and argyrophilic grain disease: Neurofibrillary pathology made up of hyperphosphorylated tau is the common feature of a family of neurodegenerative disorders collectively termed tauopathies, which include Alzheimer’s disease (AD), argyrophilic grain disease (AGD), Pick’s disease (PiD), progressive supranuclear palsy (PSP), corticobasal degeneration (CBD) and several others (Tolnay and Probst, 1999; Lee et al., 2001).