TGF-β, secreted by cancer cells or other cell types in the surrounding microenvironment, also encourages GBM neovascularization, mainly by augmenting the levels of the pro-angiogenic factor insulin-like growth factor-binding protein 7 (IGFBP7) in the tumor endothelial fraction [168]. The gene discussed is IGFBP7; the disease is glioblastoma.