A previously almost universally fatal malignancy has now been converted into a chronic disorder with near normal life expectancy.3,4 However, even after more than decade-long periods of continuous TKI administration, the majority of CML patients cannot stop their treatment without disease relapse.5 One explanation, perhaps the most plausible, to this limited potential of achieving cure with only TKI, is resistance of the CML stem/progenitor cell population to ABL1-specific TKI monotherapy. This evidence concerns the gene ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive.