Plasma biomarkers such as higher phosphorylated tau (pTau) and lower Aβ42/40 ratios can differentiate AD from both cognitively unimpaired individuals and those with non-AD neurodegenerative disorders.4-8 Both plasma pTau181 and Aβ42/40 are correlated with clinical disease severity in AD and with cognitive decline in cognitively normal elderly.9,10 Moreover, both pTau181 or pTau217 and combinations of plasma Aβ42/40 and pTau217 markers miight predict progression to Alzheimer’s dementia in cognitively unimpaired individuals.11,12. Here, MAPT is linked to Alzheimer disease.