The abnormal vascularization resulting from the activation of Hypoxia-Inducible Factor 1 subunit α (HIF1α)-responsive genes, such as vascular endothelial growth factor (VEGF) and interleukin (IL)-8, combined with a disrupted blood–brain barrier (BBB), facilitates immune cell infiltration, which exacerbates GBM growth. The gene discussed is VEGFA; the disease is glioblastoma.