Thus, for CML patients not reaching DMR on prolonged TKI monotherapy and for whom achieving TFR is considered important, or for those not even reaching major molecular response (BCR-ABL1 < 0.1% IS), the concept of adding a non ABL-directed, molecularly targeted drug to a TKI may appear highly appropriate. This evidence concerns the gene ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive.