To overcome the incapability of prospective separation of intraindividual EVI1-high cells in human leukemias, we used our original Evi1+/GFP mice, developing two types of CML-CP model to show that Evi1 is a valuable marker for CML stem cells. This evidence concerns the gene RUNX1 and chronic myelogenous leukemia, BCR-ABL1 positive.