BCR and chronic myelogenous leukemia, BCR-ABL1 positive: However, with a focus on suppressing the activity of the BCR-ABL1 kinase, they used K562 cells (a human CML cell line that expresses the wild-type variant of the BCR-ABL1 enzyme), Ba/F3 BCR-ABL1WT cells, and unmodified Ba/F3 cells [23].