Immunofluorescence with anti-CRMP5 for staining of the tumor cells and with anti-Glut1 and anti-ZO1 for staining of BBB. In low grade gliomas (grade II oligodendroglioma, upper panels; Case #3 on Table 1), a few morphologically differentiated tumor cells do not disrupt the BBB that appears well preserved with maintained Glut1 and ZO1 staining. Scale bar, 50 µm. High grade glioma (grade III astrocytoma, middle panels; Case #5 on Table 1) show an increased density of blood vessels with discontinuous Glut1 and lost of ZO1 dotted staining. Scale bar, 100 µm. In GBM (grade IV astrocytoma, lower panels; Case #26 on Table 1), the CRMP5 expressing tumor cells are morphologically heterogeneous. The blood vessels show highly disrupted BBB with losing of Glut1 and ZO1 staining. Scale bar, 40 µm. Objective lens, Olympus UPlanSAPO 40×/0.95 Oil.