The present invention discloses an extracellular/epidermal growth factor polypeptides and polynucleotides encoding such polypeptides. Also provided is a procedure for producing such polypeptides by recombinant techniques and therapeutic uses of the polypeptides which include induction of DNA synthesis, stimulating wound healing, treating neurological disorders, treating ocular disorders, treating kidney and liver disorders and stimulating embryogenesis and angiogenesis. Also disclosed are antagonists against such polypeptide and their use as a therapeutic to treat neoplasia. Also disclosed are diagnostic assays for detecting altered levels of the polypeptide of the present invention and mutations in the nucleic acid sequences which encode the polypeptides of the present invention.