GFAP and Hydrocephalus: Clinically, high levels of proteins such as thrombopoietin (17), ferritin (18), nerve growth factor (19), chondroitin sulfate proteoglycan (20), transforming growth factor beta 1 (21,22), transforming growth factor beta 2 (20), S-100 protein (23,24), glial fibrillary acidic protein (GFAP) (24), neuron specific enolase (NSE) (24), myelin basic protein (MBP) (24), and vascular endothelial growth factor (25) within ventricular CSF, which may contribute to an elevation in osmolarity, have been observed in patients with hydrocephalus.