BCR and chronic myelogenous leukemia, BCR-ABL1 positive: Although complete loss of Evi1 causes embryonic lethality in mice,25,55Evi1+/− mice have no sign of BM failure over a year and are fertile with a decreased size and function of HSCs.25,35 EVI1 has been reported to be relevant to BCR–ABL tyrosine kinase activity.27 Collectively, it is supposed that Evi1 reduction may permit the reversal of CML at the partial expense of HSCs.