GFAP and Alzheimer disease: On the contrary, the accuracy of the plasma Aβ42/40 ratio, GFAP, or NfL levels to predict AD pathology seems to be lower than that of p‐tau markers, although only few studies have investigated their association with neuropathologic measures of AD pathology (Thijssen et al, 2020; Smirnov et al, 2022; Winder et al, 2022).