GFAP and Alzheimer disease: A high level of GFAP is commonly detected by positron emission tomography (PET; Carter et al., 2012, 2019; Verberk et al., 2020; Calsolaro et al., 2021; Chatterjee et al., 2021), in the blood (Goetzl et al., 2018; Cicognola et al., 2021) or CSF (Sathe et al., 2019) of MCI and AD patients.