Recombinant Murine Acidic Fibroblast Growth Factor. Murine aFGF, encoded by the FGF1 gene, is a member of the fibroblast growth factor (FGF) family. Fibroblast growth factor was found in pituitary extracts in 1973 and then tested in a bioassay that caused fibroblasts to proliferate. After further fractionating the extract using acidic and basic pH, two different forms have isolated that named acidic fibroblast growth factor (FGF-1) and basic fibroblast growth factor (FGF-2). Murine aFGF shares 52 % amino acid sequence identity with bFGF. Murine aFGF shares 96 % amino acid sequence identity with human aFGF, so it exhibits considerable species crossreactivity between murine and human aFGF. In mammalian FGF receptor family has 4 members, FGFR1, FGFR2, FGFR3, and FGFR4, and 1, 2, 3 have 2 sub-types b, c. aFGF can bind and activate all 7 different FGFRs. Affinity between aFGF and its receptors can be increased by heparin or heparan sulfate proteoglycan. aFGF plays an important role in the regulation of cell survival, cell division, angiogenesis, cell differentiation and cell migration. aFGF are also involved in a variety of biological processes, including embryonic development , morphogenesis, tissue repair, tumor growth and invasion.