The IDH enzymes catalyze the oxidative decarboxylation of isocitrate to alpha-ketoglutarate (α-KG), producing nicotinamide adenine dinucleotide phosphate (NADPH) in the process via the citric acid cycle. Eukaryotic cells express two distinct classes of IDHs that utilize either NAD or NADP as their cofactors and serve diverse biological functions. NAD-dependent IDH is localized to the mitochondrial matrix and is well known for its central role for energy production in the Krebs cycle. NADP-dependent IDHs are primarily located either in mitochondria or cytoplasm . Each NADP-dependent isozyme is a homodimer. Mutations of Arg132 of human IDH1 result in a reduced ability of the enzyme to convert isocitrate to alpha ‑ketoglutarate, but the enzyme acquires the ability to generate 2-hydroxyglutarate (2HG) from alpha‑ketoglutarate，2-HG is elevated in several tumor types, including a subset of AMLs.