HOXA5 and acute lymphoblastic leukemia: HoxA5 along with HoxA9 is highly expressed in human ALL with MLL gene translocation and associated with poor prognosis of the disease51,52; Gsk3b and c-Myb enhance oncogenic potential of aging HSCs53,54, and Dnmt1 mediates silencing of genes marked by bivalent chromatin domains in leukemic progenitor cells55.