ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive: Lymphoblastic lymphoma (LBL) is usually of T-cell origin and B-lymphoblastic lymphoma (B-LBL) accounts for about 10% to 15% of cases.[1] The BCR/ABL gene mutation (Ph+) is the most common cytogenetic abnormality in chronic myeloid leukemia (CML) as well as in a subset of B-lineage acute lymphoblastic leukemia (B-ALL).