Another feature evaluated in this study was the ability of ABY-029 to recognize positive margins in which migratory cells are presented (Fig. 3). Tumor cells cannot only migrate through blood vessels to infiltrate the normal brain, but also can be derived from the main tumor mass and migrate in surrounding brain tissue as seen by ABY-029 fluorescence in Fig. 3a.Fig. 3.These images represent the presence of fluorescent (EGFR) tumor cells at the margin of the primary tumor mass. a Ex vivo fluorescence analysis. b H&E staining (×0.6 magnification). c H&E staining (×10 magnification) and visualization of tumor cells migrating into normal brain tissue. The last row corresponds to sham surgery and, therefore, serves as a control brain tissue.