Fluorescence in situ hybridization (FISH) to identify BCR-ABL1 in interphase nuclei and mutational analysis of the BCR-ABL1 kinase domain (KD) are used in certain clinical circumstances.     ///    " Monitoring treatment responses in chronic myeloid leukemia (CML) is based on complete blood counts (CBCs) to determine hematologic response, karyotyping of bone marrow metaphase cells to delineate cytogenetic response and quantitative reverse transcription polymerase chain reaction (qPCR) to quantify expression of BCR-ABL1 mRNA (molecular response. "    ///    "Today many laboratories report BCR-ABL1 qPCR results on the international scale (IS), a system based on the conversion of laboratory-specific numerical values to conform to a universal scale. "