In contrast to p-tau181, GFAP showed higher overall diagnostic accuracy in plasma than in CSF (AUC 0.703 vs. 0.584, p = 0.005) (Table 3), especially in the distinction between AD and FTD (AUC 0.632 vs. 0.818, p < 0.001) and between AD and PSP (AUC 0.575 vs. 0.765, p = 0.008). This evidence concerns the gene GFAP and Alzheimer disease.