GFAP and Alzheimer disease: We then repeated the ROC analyses for p-tau181 and GFAP after excluding the patients with CSF A+ and found a significant improvement in the diagnostic accuracy for AD vs. CBS (p-tau181 AUC from 0.854 to 0.972; GFAP AUC from 0.616 to 0.758) and AD vs. DLB (p-tau181 AUC from 0.806 to 0.905; GFAP AUC from 0.578 to 0.707).