MAPT and argyrophilic grain disease: Soluble microtubule-associated protein Tau assembles into insoluble, filamentous, and hyperphosphorylated intracellular inclusions in a number of human neurodegenerative diseases, which include Alzheimer disease (AD),8 tangle-only dementia, Pick disease, argyrophilic grain disease (AGD), progressive supranuclear palsy, corticobasal degeneration, and chronic traumatic encephalopathy (1).