Additionally, a gold nanoprobe labeled with a heterobivalent (HB) peptide ligand, HB-Au-NPs, has demonstrated good results in esophageal cancer imaging, where it can specifically target overexpressed epidermal growth factor receptor (EGFR) and tyrosine kinase receptor 2 (ErbB2) in cancer cells. The gene discussed is ERBB2; the disease is esophageal cancer.