MAPT and Alzheimer disease: It would provide molecular blood biomarker support for SCD as a transitional stage 2 between the fully asymptomatic stage 1 and stage 3 according to the NIA-AA Research Framework; plus – at the same time- pave the path for a blood-based signature of the ATN AD scheme (with p181 representing T/tau, and NfL representing N/neurodegeneration), thereby also facilitating the NIA-AA’s 2023 proposal to include blood-based biomarker in this classification scheme [34].