A distinct pattern of tau accumulation is observed in each tauopathy: tau aggregates are present in either or both forms of tau isoforms – for example, 3-repeat tau in Pick’s disease; 4-repeat tau in corticobasal degeneration, progressive supranuclear palsy, and argyrophilic grain disease; and both 3-repeat and 4-repeat tau in AD (Lewis and Dickson, 2016). This evidence concerns the gene MAPT and frontotemporal dementia.