MAPT and Alzheimer disease: These findings, in addition to the CSF-plasma correlations observed in the DDI cohort, might suggest that, while in CSF, the 3 p-tau markers are all sensitive for detecting AD-related pathology, in blood, potential peripheral contribution of p-tau181 and p-tau231 could affect the diagnostic and prognostic performance of these markers while plasma p-tau217 seems to be less affected by peripheral factors and a more accurate reflection of AD pathology.