IDH2 and glioma: In both gliomas and AML, mutations in IDH genes have been suggested as a very early, and perhaps founder mutations, although in neither disease does IDH mutation appear to be able to induce transformation on its own.55, 56, 57, 58 What is common to all three genes is that they are either situated directly within the mitochondrial matrix (SDH, FH, and IDH2) or their metabolic activity directly affects that of the mitochondrion (IDH1).