MAPT and Alzheimer disease: Since plasma p-tau variants have been shown in multiple antemortem and postmortem studies to associate with Aβ pathophysiology across the AD continuum9,10,12,27,33 and demonstrate higher robustness than plasma Aβ42/40 ratio2,24, we sought to establish a blood biomarker-based two-feature A/N classification system by combining it with BD-tau.