RUNX1-ETO and RUNX1-EVI1 also both require additional secondary mutations before they can cause AML in mice (Cuenco et al., 2000, Cuenco and Ren, 2001, Yuan et al., 2001), but RUNX1-EVI1 promotes a more aggressive leukemia with a reduced latency (Cuenco et al., 2000, Maki et al., 2006, Schessl et al., 2005, Schwieger et al., 2002). This evidence concerns the gene MECOM and acute myeloid leukemia.