GFAP and Alzheimer disease: The study included 563 participants from the Chinese Preclinical Alzheimer’s Disease Study (CPAS) and 243 from Alzheimer’s Disease Neuroimaging Initiative (ADNI), all of whom underwent Aβ PET, magnetic resonance imaging (MRI), neuropsychological assessments, and plasma biomarker analyses (GFAP, pTau181, pTau231, pTau217), with subsets undergoing Tau PET.