It is speculated that the amplification of the BCR/ABL1 fusion gene by duplication of Ph and tetraploidy led to the progression of CML with the e19a2 transcript..     ///    "Nine months after starting imatinib, fluorescence in situ hybridization (FISH) with the BCR/ABL-ES fusion probe revealed 96% and 3% of bone marrow cells with one and two BCR/ABL1 fusion signals, respectively. "    ///    FISH analysis confirmed the presence of cells with two to five BCR/ABL1 fusion signals. 