MAPT and neurodegenerative disease: Our study has several strengths, including the large sample size and the deeply phenotyped participants with cross-sectional and longitudinal Aβ- and tau-PET, validation in external datasets and comparisons with other neurodegenerative diseases This work was limited to CSF and we acknowledge that future studies integrating CSF and plasma proteomics could help identify more accessible markers of interest to refine disease staging.