TWIST1 and acute myeloid leukemia: In spite of the facts that the expression of Bmi1 could be regulated by Twist1 and that Bmi1 is constantly associated with the ‘stemness' properties of AML and hematopoietic cells, Twist1, as a transcriptional factor, might affect leukemogenesis through other unidentified pathways that are independent of Bmi1 activity.