a. Representative ex vivo fluorescence imaging of tumor and organs harvested from mice bearing 4T1 primary tumor xenografts at 4 h after injection of ZD2-Cy5.5. Numbers denote: 1, heart; 2, lung; 3, liver; 4, muscle; 5, 4T1 tumor; 6, brain; 7, kidney; 8, spleen. b. Histological analysis of the binding of ZD2 peptide and EDB-FN distribution. Merged channel of ZD2 and EDB-FN showed the colocalization of ZD2-Cy5.5 and EDB-FN.