HIF1A and glioblastoma: These data indicate that the expression of PDGFRA and PDGFD in GBM cells depends more on HIF1α compared with the expression of other receptors and growth factors, such as PDGFB. Moreover, surgically resected primary LGG (n = 3) and GBM (n = 6) tissue samples were compared for HIF1α, PDGFRα and PDGF-D levels by Western blot.