ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive: The dysregulationof Abl1 kinase activity is associated with several pathological conditions,most notably chronic myeloid leukemia (CML).3−5 In CML, theBCR–ABL fusion protein, resulting from a chromosomal translocation,exhibits constitutive kinase activity that drives uncontrolled cellproliferation and resistance to apoptosis.