BCR and chronic myelogenous leukemia, BCR-ABL1 positive: Chronic myeloid leukemia (CML) is a clonal myeloproliferative neoplasm characterized by t(9;22)(q34;q11.2) reciprocal translocation, resulting in the fusion of the Abelson gene (ABL1) on chromosome 9q34 with the breakpoint cluster region (BCR) gene on chromosome 22q11.2, forming the BCR::ABL1 fusion gene [10].