ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive: In the future, the genomic editing of ABL described in this study could be improved by addressing the following concerns: (a) primary cultures of leukemia cells from CML patients are required to assess anticancer efficacy; (b) lentivirus transfection may vary between primary leukemia cells and the K562 cell line; (c) a primary culture immortalization system for leukemia cells is essential for future preclinical anticancer evaluation; (d) a systemic leukemia model using primary culture cells would be the best platform to mimic a gene therapy approach targeting ABL or other oncogenes.