{"type":"root","children":[{"type":"paragraph","children":[{"type":"text","value":"Glial fibrillary acidic protein or GFAP is a Type III protein of the intermediate filaments principally found in astrocytes in the central nervous system, but can also be found in neurons, hepatic stellate cells, kidney mesangial cells, pancreatic stellate cells, and Leydig cells. It has a role in the cytoskeleton of the astrocyte and\n possibly many other stellate-shaped cells."}]},{"type":"paragraph","children":[{"type":"text","value":"Antibodies to GFAP are very useful as markers of astrocytic cells. In addition, many types of brain tumors, presumably derived from astrocytic cells, heavily express GFAP. This marker is mainly used to distinguish neoplasms of astrocytic origin from other neoplasms in the central nervous system."}]}]}