In particular, except for frontotemporal dementias (FTDs) such as Pick’s disease (PiD), that mostly include aggregates of Tau 3R isoform, known tauopathies comprise all six 3R and 4R isoforms (e.g., Chronic Traumatic Encephalopathy—CTE—and Alzheimer’s disease—AD, Primary Age-Related Tauopathy—PART, Familial British Dementia—FDB, Familial Danish Dementia—FDD), or only Tau 4R isoforms (i.e., Corticobasal Degeneration—CBD, Progressive Supranuclear Palsy—PSP and Argyrophilic Grain Disease—AGD, Astrogliopathy—ARTAG, Globular Glial Tauopathy—GGT) [83,84,85,86]. Here, MAPT is linked to argyrophilic grain disease.