IL6 and glioblastoma: Consistently, studies based on the GBM-bearing mice model indicate the down-regulation of TJs proteins (including Claudin-5, Occludin and ZO-1) in microvasculature may be induced by cytokines, such as interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), interferon-γ and NF-κB [48,49].