EGFR and central nervous system cancer: Monovalent (EG2), bivalent (EG2-hFc), and pentavalent (V2C-EG2) nanobodies directed against the epidermal growth factor receptor (EGFR) and its variant III (EGFRvIII) have been successfully employed for in vivo fluorescence imaging of orthotopic high-grade glioma-bearing mice [57].