GFAP and Stroke: We found significant correlations between functional outcome 3 months after the index stroke and serum biomarker levels of NfL [p < 0.0001; r = 0.47 (95% CI: 0.36–0.58)] and GFAP [p < 0.0001; r = 0.48 (95% CI: 0.37–0.58)].