FGF (Fibroblast Growth Factor) is a protein that is involved in wide variety of processes related to normal development of various cells including fibroblasts, as well as angiogenesis, wound healing and so on. The mammalian FGFR (FGF receptor) family has four members: FGFR1, FGFR2, FGFR3 and FGFR4.