To determine its impact on leukaemic haematopoiesis, we induced acute or chronic myeloid leukaemias (AML or CML) in mice by enforced expression of MLL‐AF9 or BCR‐ABL, respectively, in Tgif1+/+ or Tgif1−/− haematopoietic stem and progenitor cells (HSPCs) and transplanted them into syngeneic recipients. Here, MLLT3 is linked to chronic myelogenous leukemia, BCR-ABL1 positive.