Stem cell maintenance and disease progression in chronic myeloid leukemia.

Chronic myeloid leukemia (CML) is a cancer of blood cells driven by the BCR-ABL1 oncogenic protein tyrosine kinase, which is the product of a reciprocal chromosomal translocation known as the Philadelphia chromosome. Discovery of tyrosine kinase inhibitors targeting the BCR-ABL1 kinase revolutionized CML therapy, but these drugs are unable to eradicate the disease due to the presence of a drug-insensitive stem cell population that sustains continued growth of the malignant cells. Resistance to therapies also increases the risk of relapse and disease progression to a more advanced phase. This review discusses emerging issues in CML research, and describes recent progress in elucidating the mechanisms of CML stem cell maintenance and disease progression.