Again, in GBM regions with hyperintense FLAIR signal that did not enhance on Gd-MR, the BBB of vessels surrounded by tumor cells was not disrupted, as demonstrated by the continuous ZO-1 immunoreaction of Glut-1 positive vessels and by Claudin-5 expression of lectin-positive vessels (Figure 4C,D, Supplementary Figures S7 and S8A–D). This evidence concerns the gene SLC2A1 and glioblastoma.