GFAP and Alzheimer disease: A recent study demonstrated that plasma GFAP levels were higher in a group of 33 CU+ individuals compared with 63 CU– individuals (AUC = 0.795).16 Preceding studies showed that plasma GFAP levels were associated with both clinical diagnosis and Aβ status.25 Another study revealed a quadratic (inverted U-shape) association between plasma GFAP levels and Aβ deposition.26 To our knowledge, no other studies investigated the whole AD continuum or included participants with preclinical AD, and no other studies compared plasma and CSF compartments in the same individuals.