CEACAM5 and colorectal carcinoma: In a LS174T human CRC mouse model, bivalent haptens labeled with various radionuclides (i.e., indium-111, yttrium-90 and iodine-131) against the anti-CEA × anti-DTPA-In BsF(ab’)2 proved to have a higher targeting efficiency than the monovalent hapten [56].