IDH2 and myeloid neoplasm: As previously described in myeloid malignancies,7, 21 the first/early events were mainly mutations in epigenetic regulators (ASXL1, DNMT3A, IDH2; cases #3, #6, #9, #11), chromosome 20q deletions (case #4), transcription factors (RUNX1; cases #5, #8) or splicing machinery (U2AF1, case #10), with a frequent early accumulation of epigenetic events in a dominant clone.