TNF and glioma: Additionally, various cytokines in the CSF such as tumor necrosis factor-α (TNF-α), transforming growth factor-β (TGF-β), interferons, interleukins (IL) 2, 4, 6, 8 10, 12 and 13, hypoxia-inducible factors (HIF), granulocyte–macrophage colony-stimulating factor (GM-CSF) and vascular endothelial growth factor (VEGF) seem to play a role in the regulation of the glioma microenvironment [18].