TGFB1 and glioma: In particular TGF-β1 isoform may contribute to tumor pathogenesis by direct support of tumor growth, self-renewal of glioma initiating stem cells and stimulating expression of the vascular endothelial growth factor as well as the plasminogen activator inhibitor and some metalloproteinases that are involved in vascular remodeling, angiogenesis and degradation of the extracellular matrix [24–25].