HMOX1 and chronic myelogenous leukemia, BCR-ABL1 positive: In summary, we suggest that HO-1 plays a dual role in imatinib resistant CML: endogenous ER resident HO-1 can represent a survival factor for leukemic cells, but overexpression of ER resident HO-1 does not lead to imatinib resistance, whereas translocation of HO-1 to the nucleus and cytosol supports imatinib resistance in some but not all cell lines.