We reported previously that CML cells expressing the BCR/ABL1 fusion gene, accumulated a high level of reactive oxygen species (ROS) due to deregulated mitochondrial electron transport chain, which in turn led to genomic instability, resulting in imatinib resistance.     ///    Reactive Oxygen Species and Mitochondrial DNA Damage and Repair in BCR-ABL1 Cells Resistant to Imatinib..     ///    "ROS level in cells with primary resistance, which resulted from the T315I mutation in BCR/ABL1, was higher than in cells with acquired resistance. "