CD34 and chronic myelogenous leukemia, BCR-ABL1 positive: Similarly, accumulation of mitoxantrone in primary chronic myeloid leukaemia (CML) CD34+ cells overexpressing BCRP was significantly increased by 5 μM of imatinib, confirming the activity of this TKI as a BCRP inhibitor (Jordanides et al, 2006).