Plasma GFAP is higher in Aβ-positive cognitively unimpaired individuals at risk of developing AD (Chatterjee et al., 2021), and longitudinal investigations have observed that plasma GFAP can predict subsequent conversion of mild cognitive impairment (MCI) patients to AD with an area under the receiver operating characteristic curve of 0.84 (95% CI 0.77–0.91) (Cicognola et al., 2021). This evidence concerns the gene GFAP and Alzheimer disease.