IDH1 and glioma: Other lines of evidence showed that D-2-HG, but not L-2-HG, stimulates the activity of the prolyl hydroxylase PHD2, which results in the reduced expression of HIF-1/2α.34 More effort is encouraged to elucidate the relationship between D-2-HG and the hypoxia-sensing pathway in glioma and other IDH1-mutated malignancies.