FGF-8 is a heparin binding protein of the FGF family which works to control cell division, differentiation, and function. These proteins are especially prominent during prenatal development and postnatal growth. FGF-8 can be spliced in four different ways. The products of the FGF-8 splicing events are as follows: FGF8A, 8B, 8E and 8F. This recombinant product represents isoform 8B and is expressed in human 293 cells as a monomeric glycoprotein with a molecular mass of 30 to 45 kDa. This wide molecular mass is due to glycosylation, which is absent when this cytokine is expressed in E. coli.