In the TRIAD cohort, levels of plasma and CSF GFAP were higher across the AD continuum, namely, in Aβ+ CU (CU+) individuals (ie, preclinical AD), individuals with Aβ+ MCI (MCI+; ie, MCI due to AD), and individuals with AD dementia (Figure 1A). This evidence concerns the gene GFAP and Alzheimer disease.