ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive: The BCR-ABL inhibitors are clearly a very important advance since they are able to induce durable remissions in the majority of CML patients in chronic phase, but they are not usually curative since most patients relapse if therapy is discontinued, probably because quiescent CML stem/progenitor cells are not killed by the drugs and are able to reproduce the disease [9, 72].