BCR and chronic myelogenous leukemia, BCR-ABL1 positive: Chronic myeloid leukemia (CML) is a clonal malignant disorder of pluripotent hematopoietic stem cells (HSCs), characterized by the presence of Philadelphia chromosome (Ph) translocation t(9;22)(q34;q11), leading to the formation of the novel BCR-ABL fusion gene (1).