TGFB1 and glioblastoma: TGF-β is known to be abundantly present in the tumor microenvironment of GBM and has been linked to multiple processes associated with GBM, such as angiogenesis, invasion/migration, immunosuppression and stemness.17,18 We show that this mesenchymal shift in GBM is associated with enhanced migration and invasion capacity of tumor cells in cell culture and intracranial mouse models.