TGFB2 and glioblastoma: However, phase II clinical trials of galunisertib7, a TGFβ receptor type I (TβRI) inhibitor, and trabedersen8, a TGFβ2 inhibitor, failed to improve the overall survival of GBM patients, which suggests the need for further understanding of the pathological implications of TGFβ signaling in GBM.