ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive: Interestingly, resistance appears not only to traditional chemotherapy but also to targeted therapies such as tamoxifen, which targets the oestrogen receptor (ER) in breast cancer (Ali and Coombes, 2002); imatinib, which targets the kinase activity of the translocated BCR-ABL in chronic myelogenous leukaemia (CML) (Weisberg et al, 2007); or gefitinib, which inhibits epidermal growth factor receptor (EGFR) kinase (Engelman et al, 2007).