OCLN and glioblastoma: Yang et al. indicated that VEGF could increase the permeability of BBB in GBM by a paracellular pathway (down-regulation of Claudin-5 and Occludin) and a transcellular pathway (up-regulation of caveolin-1 and caveolin-2), and cGMP/PKG/NF-κB signaling pathway might also be involved in VEGF-mediated BBB disruption [40].