BCR and chronic myelogenous leukemia, BCR-ABL1 positive: In vitro cell line models have been used extensively to characterise resistance to the first and second generation TKIs in CML: our group and others have previously generated imatinib, nilotinib and dasatinib resistance in human and/or murine BCR-ABL1+ cell lines by culturing with gradually increasing concentrations of TKIs in a step-wise manner [16, 19, 28, 29].