Plays an important role in the regulation of cell proliferation, cell differentiation and cell migration. Required for normal ossification and bone development. Stimulates hepatic and intestinal proliferation (By similarity). Interacts with FGFR3 and FGFR4. Mainly expressed in the lung. Not detected in brain, heart, liver, kidney and small intestine. Expressed in several discrete regions at embryonic days 14.5 and 19.5 but not 10.5. At E14.5, expressed in isthmus, pituitary, spinal cord, tongue, intervertebral disk, dorsal root ganglion and pelvis. At E19.5, expressed in lung and anterior pituitary. Belongs to the heparin-binding growth factors family.