MAPT and Alzheimer disease: Phospho-tau seeding and spreading occurs following inoculation of preformed synthetic tau fibrils [61], and injection of fibrillar-enriched fractions from human or mouse brain homogenates of tauopathies, including AD, only tangle dementia, argyrophilic grain disease, PSP, and CBD, injected into the brain of transgenic mice expressing 4R human tau or human mutant tau [2, 9, 14–16].