ABL1 and acute leukemia: Indeed, in the acute promyelocytic leukemia, the treatment based on the molecular instead of the clinical relapse has been successful (10), and also in chronic myeloid leukemia the guidelines state the switch to another tyrosine kinase inhibitor when the BCR-ABL1/ABL1 ratio does not meet the optimal value at a fixed timpe-point, so reducing the risk of transforming it into acute leukemia (11).