MDM2 and chronic myelogenous leukemia, BCR-ABL1 positive: To test our hypothesis, we used a potent MDM2 inhibitor (MDM2i), idasanutlin (IDASA) to upregulate p53 in CML cells in vitro and in vivo and examined how this affected CFC, engraftment, and multilineage potentialities, and maintenance of a CD34+CD38− cell pool (all qualitative or quantitative metrics of self-renewing LSC).