Fibroblast growth factor 1 （FGF-1）, known as acidic fibroblast growth factor （FGF-Acidic）, is one of the best characterized members of the FGF superfamily. FGF-1 is a powerful mitogen exhibiting strong action on numerous different cell types. It plays a role in various stages of development and morphogenesis, as well as in angiogenesis and wound healing processes. FGF-1 is released extracellularly as a disulfide-linked homodimer and is stored in complex with extracellular heparan sulfate. The association of FGF-1 with heparan sulfate is a prerequisite for its subsequent interaction with FGF receptors. Ligation triggers receptor dimerization, transphosphorylation, and internalization of receptor/FGF complexes.