GFAP is an intermediate filament protein with a molecular weight of 51 kDa, which participates in the formation of cytoskeleton and maintains its tension strength. GFAP is mainly distributed in astrocytes and ependymal cells of the central nervous system, Schwann cells and satellite cells of intestinal ganglion of the peripheral nervous system, myoepithelial cells and chondroblasts. It is mainly used for the diagnosis and differential diagnosis of astrocytoma, including astrocytoma, astroblastoma, mixed glioma, pleomorphic glioblastoma and non astrocytoma, including a few gliomas, most ependymomas and other central nervous system tumors.