Metastatic foci of fluorescent human breast cancer cells that had developed in the lungs of immune deficient mice. The number and size of metastases found in animals treated with breast cancer patient derived antibody were much reduced (lower image) compared to animals treated with ineffective control antibody (upper image).
Convergent evolution of critical sequences in ligand-mimetic antibodies and natural ligands causes both to target the same receptor protein (Artwork by Dr. Art Olson)