ROC analysis pointed to p181-Tau as the best separator, as could be expected given its importance as a leading AD biomarker in all biofluids; however, its performance was closely followed by those of GluR2 and proBDNF, while GAP43, NRGN, Syntaxin-1, and PSD95 also showed significant AUC values. Here, GAP43 is linked to Alzheimer disease.