These results and the observation that the CML stem/progenitor cells treated with the drug combination showed the characteristic morphology of apoptosis, but not pyroptosis (Supplementary Fig. 4), suggest that the combination treatment exerts its antiviability effect on these primary cells through the induction of apoptosis accompanied by the downregulation of MCL1 protein expression. Here, MCL1 is linked to chronic myelogenous leukemia, BCR-ABL1 positive.