A Nature Communications study validated blood biomarkers that correspond to Alzheimer’s disease progression across cognitive stages in community cohorts. The research identified plasma signatures that rise with advancing pathology and cognitive impairment, enabling less invasive disease staging and monitoring. Authors highlighted assay reproducibility and potential for wider screening in population studies, while noting the need for harmonized thresholds in clinical settings. Blood biomarkers offer an alternative to cerebrospinal fluid or PET imaging for tracking neurodegeneration.