ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive: Chronic myeloid leukemia (CML) is a hematopoietic malignancy in which hematopoietic stem cells (HSCs) are transformed by the BCR::ABL1 fusion gene generated from a reciprocal translocation [t(9;22)(q34;q11.2)] (Cortes et al., 2021).