RUNX1 and acute myeloid leukemia: Finally, to model the effects of coexistent oncogenic RAS mutations, which are present in a subset of AML1-ETO/ASXL2-mutant AML patients25, expression of NRASG12D in Mx1-cre Aml1-Eto Asxl2fl/WT and Mx1-cre Aml1-Eto Asxl2 WT BM backgrounds resulted in further collaborative effects in the AML1-ETO/ASXL2 haploinsufficient background (Fig. 5d and Supplementary Fig. 9e–h).