MLLT3 and acute myeloid leukemia: To examine the role of Zeb2 in AML progression in vivo, we have used Rosa26-CreERT2; Zeb2fl/fl BM and an MLL-AF9 retrovirus to create primary AML leukemic cells that allowed us the ability to temporally inactivate Zeb2 in vivo in a tamoxifen-inducible manner after secondary engraftment (Fig 9A).