MEIS1 and acute myeloid leukemia: We also profiled global transcriptomes of two additional murine AML lines established by either MLL rearrangement (MLL-AF9) or co-expressed Hoxa9 plus Meis1 (A9M); MLL rearrangement is known to sustain stemness genes while co-expressed A9M is able to arrest differentiation at a myeloid progenitor stage6,33.