Chromosomal rearrangements at 3q26 are associated with poor-prognosis acute myeloid leukemia (AML)1, myelodysplastic syndromes (MDS)2, and myeloproliferative neoplasms (MPN)3, and cause activation of MECOM, a gene that encodes multiple zinc-finger (ZF) transcription factor isoforms, including three isoforms of EVI1. Here, MECOM is linked to myeloproliferative disorder.