ERBB2 and neoplasm: The KCCYSL peptide, derivatized with different metal chelators (i.e., DOTA, NOTA, CB-TE2A, and DAP) and radiolabeled with radionuclide metal ions (e.g., 111In, 64Cu, 99mTc), has been successfully used for in vivo imaging of HER2 overexpressing tumor models.