ERBB2 and cancer: Examples of these peptides for diagnostic purposes are: HER3P1 peptide labelled with 68Ga used as agent for PET imaging; ERBB2-targeted peptide 1-D03 labeled with 111In-DOTA used for SPECT imaging of breast carcinoma; and gastrin-releasing peptide, epidermal growth factor, and glucagon-like peptide-1 receptor tested for imaging in early cancer diagnosis.