GFAP and Alzheimer disease: Corresponding AUCs for tTau, NfL, and GFAP ranged between 0.81 and 0.83 (p < 0.001 for all analytes) and adding all three to the base model plus pTau181 did not increase the ability to discriminate between AD and CN compared to the model with pTau181 (AUC = 0.91; CI: 0.86–0.95).