CEACAM5 and colonic neoplasm: A new peptide, IMP-325, In-DOTA-d-Tyr-d-Lys(HSG)-d-Glu-d-Lys(HSG)-NH2, was labeled with 124I and tested in nude mice bearing LS174T human colonic tumors that were given anti-CEA/anti-HSG bs-mAb.