Initially, the production of d-2-hydroxyglutarate in gliomas, secondary glioblastomas, and AML by mutant IDH2 results in a decrease of 2OG and hence depletion of succinate, fumarate, and malate from the rest of the Krebs cycle [23, 36, 39]. The gene discussed is IDH2; the disease is acute myeloid leukemia.