GFAP and Alzheimer disease: Other biomarkers of AD pathogenesis include CSF or plasma Neurofilament light chain (NfL) and Glial Fibrillary Acidic Protein (GFAP) for the diagnosis of AD, MRI to assess brain atrophy, and positron emission tomography (PET) imaging of Fluorodeoxyglucose (FDG) uptake and synaptic vesicle protein 2A (SV2A) for assessing brain hypometabolism (Jack et al., 2024a; Hansson, 2024; Jack et al., 2024b) and loss of synaptic density (Wang et al., 2024a; Wang et al., 2024b; Mecca et al., 2022a; Mecca et al., 2022b; Mecca et al., 2020).