Increased GFAP concentrations have been detected in CSF and blood of AD patients, with rising levels already at the preclinical phase of the disease, as well as an association between GFAP levels and cerebral amyloid pathology, brain atrophy, cognitive decline, and future conversion to dementia (Elahi et al., 2019; Oeckl et al., 2019; Asken et al., 2020; Verberk et al., 2020; Benedet et al., 2021; Chatterjee et al., 2021; Cicognola et al., 2021). Here, GFAP is linked to Brain atrophy.