GFAP and early-onset autosomal dominant Alzheimer disease: Indeed, a combination with other biomarkers seems to be an essential condition for the putative use of GFAP as a biomarker in Alzheimer's disease.26 Although our finding that global tau SUVR is significantly correlated with cognitive decline is in line with previous studies,59 this also supports the hypothesis that assessing regional tau uptake instead might offer a better prognostic value of disease progression.