Human HBEGF (Heparin Binding EGF like growth factor) is a member of the EGF family of peptide growth factors that signal through the EGF receptor, and stimulates the proliferation of smooth muscle cells, fibroblasts, epithelial cells, and keratinocytes. HBEGF is expressed in many cell types and tissues, including bronchial epithelium, visceral and vascular smooth muscle, CD4+ T cells, glomerular podocytes, keratinocytes, macrophages and certain tumor cells. Mature HBEGF is a soluble peptide that arises from the proteolytic processing of the 208 amino acid type-I transmembrane form and exhibits the ability to specifically bind heparin and heparin sulfate proteoglycans.