MAPT and Mental deterioration: NfL and GFAP have both been shown to be related to baseline cognition, cognitive decline, and clinical progression as individual predictors, but have not yet been studied extensively in comparison to other N biomarkers.3,48, -, 50 In a former study, we found GFAP was more strongly related to clinical progression and cognitive decline than NfL, which is in line with our current study.4 We found both GFAP and NfL predicted clinical progression beyond Aβ and p-tau, but NfL was not associated with MMSE decline.