HIF1A and glioblastoma: Since antiangiogenic therapy-induced vascular pruning is suspected to modulate tumor hypoxia in glioblastoma and other solid tumors and STAT-3 is known to activate and stabilize HIF-1α [20] and promote VEGF expression, we evaluated tumor hypoxia in tumors at the time of control and cediranib treatment failure (Fig. 4C).