The pro-inflammatory condition that follows GBM carcinogenesis may further weaken the BBB's integrity by increasing its permeability and allowing lymphocytes and monocytes from the peripheral lymphatic system to infiltrate the bloodstream.28 In addition to being an essential part of the blood-brain barrier, astrocyte cells have the ability to increase proinflammatory activity by secreting cytokines such as TNF-α, IFN-α, and TGF-β (transforming growth factor-β) [88]. This evidence concerns the gene TGFB1 and glioblastoma.