Fibroblast growth factor 13 (FGF13) is a new member of 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-13 plays an important role in the regulation of embryonic development and as a signaling molecule in the induction and patterning of the embryonic brain.