The antibodies used in this study were not specifically selected for the development of tumor-specific probes, since the focus of this study was to identify the most suitable targets; however, the antibodies in this study used for integrin αvβ6 (6.2A, Biogen Idec MA Inc.), CEA (A0155, Dako), EGFR (E30, Dako), EpCAM (323A3), and uPAR (ATN-615) react on the extracellular epitopes of their analogues and have been described for use on intact protein [52]. Here, PLAUR is linked to neoplasm.