GFAP and Alzheimer disease: GFAP in body fluids, including CSF and serum/plasma, is considered a good biomarker for the early diagnosis and prognosis of AD, especially blood GFAP, which is considered an excellent biomarker for large-scale screening (Heimfarth et al., 2022; Teunissen et al., 2022; Guo et al., 2023).