Human colon specific gene polypeptides and DNA (RNA) encoding such polypeptides and a procedure for producing such polypeptides by recombinant techniques is disclosed. Also disclosed are methods for utilizing such polynucleotides or polypeptides as a diagnostic marker for colon cancer and as an agent to determine if colon cancer has metastasized. Also disclosed are antibodies specific to the colon specific gene polypeptides which may be used to target cancer cells and be used as part of a colon cancer vaccine. Methods of screening for agonists and antagonists for the polypeptide and therapeutic uses of the antagonists are also disclosed.