ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive: Therefore, a recent proof-of-principal asthma study tested the effects of imatinib, a tyrosine kinase inhibitor designed to target ABL (Abelson murine leukemia viral oncogene homolog 1) for treatment of chronic myelogenous leukemia (CML), which also inhibits several other tyrosine kinases including c-kit (83).