GFAP and concussion: Of the seven biomarkers measured, GFAP and IL6 were each significantly elevated in both plasma (GFAP P < 0.0001, 147-fold change compared to controls; IL6 P < 0.01, 7-fold change relative to controls) and GluR2+ EVs (GFAP P < 0.001, 6-fold change compared to controls; IL6 P < 0.01, 3-fold change relative to controls) in mTBI.