Based on earlier studies of RUNX1, the following conclusions can be made: 1) RUNX1 plays an important dual role in myeloid leukemogenesis, depending on the level of its expression; 2) normal expression of RUNX1 works as a tumor suppressor, inhibiting cell proliferation and promoting differentiation of hematopoietic progenitor cells; 3) Partial deactivation of RUNX1 leads to amplification of myeloid progenitors and subsequent development of AML; and 4) further reduction of RUNX1 expression causes cell cycle arrest and cell death [23–26]. This evidence concerns the gene RUNX1 and acute myeloid leukemia.