ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive: Another study recommended that, by combined morphologic and FISH analysis, the presence of BCR-ABL1 in both the lymphoid and myeloid lineages favors the diagnosis of T-lymphoblastic BP of CML, whereas the presence of BCR-ABL in lymphoid lineage only will favor BCR-ABL-positive T-ALL [8].