MAPT and Alzheimer disease: Plasma p-tau181 can differentiate AD from non-AD neurodegenerative disorders [10, 25, 27, 29, 34, 60], detect AD neuropathology [25, 34, 60], identifies individuals with increased Aβ and tau PET retention [25, 27, 29, 41, 60], strongly associates with imminent grey matter atrophy [57] and predicts progression to AD dementia, to the same degree as CSF p-tau181 [25, 27, 44].