The 2008 World Health Organization (WHO) classification recognized acute myeloid leukemia (AML) with inv(3)(q21q26.2) or t(3;3)(q21;q26.2) and GATA1-EVI1(MECOM) rearrangement as a clinicopathologic entity, associated with poor clinical outcomes. This evidence concerns the gene MECOM and acute myeloid leukemia.