Although Aβ and tau both are relevant in AD-associated neurodegeneration, primary tauopathies such as certain frontotemporal dementias (FTD; also termed tau-positive frontotemporal lobar degeneration, FTLD-tau [18]), Pick’s disease, progressive supranuclear palsy, cortical basal degeneration, and argyrophilic grain diseases progress in the absence of overt Aβ pathology [7]. This evidence concerns the gene MAPT and argyrophilic grain disease.