Immunofluorescence staining was performed for each tumor specimen using antibodies against CD31 (anti-mouse, 1:200) (Millipore, Billerica, MA), glial fibrillary acidic protein (GFAP) (anti-rabbit, 1:1000) (Abcam, Cambridge, UK), and aquaporin 4 (AQ4) (anti-rabbit, 1:200) (Millipore). AQ4 is a marker of astrocytic foot processes and has been previously used as a reliable measure of astrocyte-endothelial cell relationship integrity [6 (link),7 (link)]. Double immunofluorescence staining was performed for CD31 and GFAP; and CD31 and AQ4, using a protocol described previously [5 (link)]. The following secondary antibodies were used at 1:1000 dilution:donkey serum anti-mouse IgG absorbing at a wavelength of 568 nm (Life Technologies, Carlsbad, CA) and donkey serum anti-rabbit IgG absorbing at a wavelength of 488 nm (Life Technologies). Immunofluorescent images were captured at ×40 magnification using a Leica (Wetzlar, Germany) LSM 510 confocal microscope, while H and E images were obtained at ×40 magnification using a Nikon (Tokyo, Japan) Eclipse Ci microscope with a Nikon DS-Fi2 camera.