Importantly, regardless of the presence of a 3q rearrangement and the exact mechanism of aberrant expression, all EVI1 overexpressing (EVI1high) leukemias are associated with a low rate of disease remission, high rates of relapse and chemotherapy resistance and very poor overall survival.26,29–31 A significant proportion of the EVI1high AML patients remains refractory, and of those who achieve complete remission,25 many relapse after a short time. Here, MECOM is linked to leukemia.