In a small series of chronic myeloid leukemia (CML) and Ph+ acute lymphoblastic leukemia (ALL) patients with multi-TKI-resistant disease, NGS showed that BCR-ABL1 KD mutation status may be much more complex than SS shows, with one or multiple low level mutants often detectable in addition to dominant mutants [16]. This evidence concerns the gene BCR and chronic myelogenous leukemia, BCR-ABL1 positive.