ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive: In the present study, a novel case of Ph chromosome-positive CML in BC with a four-way rearrangement was observed, including five chromosomal regions, 9p21, 9q34, 12p13.3, 20q11.2, 22q11.2, an unbalanced translocation t(7;8) (p11.2;q11.2), deletions of ABL and ASS genes on der(9), monosomies 8, 12 and an additional Ph chromosome.