TGFB1 and glioblastoma: To examine if BMP activation could account for treatment resistance in glioblastoma cells, we performed in vitro survival studies in three GSC lines (G144, G179, BT046) exposed to a five-day course of temozolomide (25 μM) and concomitant radiation (10 Gy/5 sessions) following treatment with BMP or TGF-b pathway agonists.