IDH2 and central nervous system cancer: It is interesting to note that elevated 2-HG in IDH mutant glioma has been shown to inhibit branched-chain-amino-acid aminotransferase 1 and 2 (BCAT 1 and 2), which are transaminases that convert branched-chain amino acids (leucine, isoleucine and valine) to their keto-acids in the cytoplasm and mitochondria, respectively25.