IDH1 and neoplasm: Originally, it was hypothesized that the aberrantly produced 2-HG by mutated IDH may compete with alpha-ketoglutarate and inhibit the prolyl hydroxylase (PHD), which in turn can lead to the pathological stabilization of hypoxia inducible factor (HIF) and induction of the expression of the major proangiogenic vascular endothelial growth factor (VEGF) and thus initiation of tumor angiogenesis [23, 24].