Fibroblast Growth Factor 9 (FGF-9) belongs to the Fibroblast growth factor (FGF) family. FGF family members possess broad mitogenic and cell survival activities, and are involved in a variety of biological processes, including embryonic development, cell growth, morphogenesis, tissue repair, tumor growth and invasion. FGF-9 plays an important role in the regulation of embryonic development, cell proliferation, cell differentiation and cell migration. In addition, FGF-9 may have a role in glial cell growth and differentiation during development, gliosis during repair and regeneration of brain tissue after damage, differentiation and survival of neuronal cells, and growth stimulation of glial tumors.