Registry of CSF, plasma, and imaging biomarkers used for AD diagnosis, staging, and monitoring. Initial v1 set covers the established A/T/N framework biomarkers (amyloid, tau, neurodegeneration) plus the newer plasma assays (p-tau217, GFAP) that are reshaping population-scale screening. Subsequent commits should add sensitivity/specificity columns from head-to-head studies, add the inflammation and synaptic biomarkers (sTREM2, neurogranin, SNAP25), and link rows to the analyses table where each biomarker has been used as a primary endpoint.