HIF1A and glioblastoma: Du et al., [9] recently reported that HIF-1α, the direct effector of hypoxia, induces recruitment of diverse bone marrow derived subpopulations, containing Tie2+, VEGFR1+, CD11b+, and F4/80+, as well as EPC and pericyte progenitors to promote neovascularization in glioblastoma.