This present invention is directed to polypeptide and polynucleotide molecules that encode a new connective tissue growth factor homolog polypeptide. The human polypeptides have been designated zCTGF4 and the mouse orthologs have been designated zCTGF2. The invention also includes antibodies, expression vectors, host cells expressing zCTGF4 and variants. Also included are methods for producing the polypeptides and using the polynucleotides and polypeptides.