To determine the diagnostic value of the discrimination threshold established in our exploratory cohort (Tau > 2.6 rIF and GFAP > 1.7 rIF), we analyzed prospectively collected plasma from a cohort of 15 glioblastoma patients and 8 control subjects without history of brain tumor (Fig. 6A,B). The gene discussed is GFAP; the disease is glioblastoma.