MCL1 and chronic myelogenous leukemia, BCR-ABL1 positive: The activators bind all antiapoptotic BCL-2 family members, whereas the sensitizers NOXA and HRK are more selective in binding MCL-1 and BCL-XL, respectively.11 BCR-ABL modulates the expression levels and/or the phosphorylation status of several BCL-2 family members, thus exerting important regulatory effects on apoptosis.12, 13, 14, 15 Furthermore, recent reports suggest important roles for several antiapoptotic BCL-2 family members in CML disease progression.16, 17, 18, 19, 20 Elevated levels of these proteins in several cancers make them promising targets for drug therapy.