ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive: The assumption that it is possible to increase the TFR rate by rotating the second-generation TKIs or changing to a third-generation option has been the rationale by many physicians (also encouraged by CML experts, and in CML reviews, advisory boards and symposia) to change the TKI in a patient who does not achieve a major molecular response (MMR; BCR::ABL1 transcripts [IS] < 0.1%) or DMR after some duration of TKI therapy.