OUTLINE: Archived serum samples are analyzed for 2-hydroxyglutarate expression by reverse-phase liquid chromatography coupled to mass spectrometry. Results are then compared with presence or absence of an IDH mutation, patients' clinical outcome, as well as age, sex, white blood cell count at diagnosis, platelet count, bone marrow blast percentage at diagnosis, circulating (serum) percentage at diagnosis, cytogenetic risk group, presence of FLT3, NPMN1, and/or TET2 mutations, specific IDH mutation, and randomization treatment group allocation.