IDH1 mutant glioma cells reduce the production of α-KG and increase HIF-1α and its target genes (GLUT1, VEGF, and PDK1) to stimulate tumor growth and angiogenesis [134], whereas IDH1 mutants have also been shown to stimulate EglN prolyl 4-hydroxylase, which destabilizes HIF-1α and diminishes the expression of its target genes to promote transformation [144]. This evidence concerns the gene HIF1A and glioma.