Basic Fibroblast Growth Factor (bFGF) is a member of the FGF family. bFGF has been shown to support the maintenance of undifferentiated human embryonic stem cells. It also stimulates the proliferation of all cells of mesodermal origin, and many cells of neuroectodermal, ectodermal and endodermal origin. bFGF is a chemotactic and mitogenic agent for endothelial cells in vitro and induces neural differentiation, survival and regeneration. It has been shown to be crucial in modulating embryonic development and differentiation and it may play a role in the modulation of angiogenesis, tissue repair, embryonic development and neuronal function in vivo. There are a variety of forms of bFGF due to N-terminal extensions. The 157 amino acid residue recombinant protein has a predicted molecular mass of approximately 17.4 kDa.