ABL1 and leukemia: Since transplantation of primary CML stem/progenitor cells is not able to generate leukemia in immunodeficient mice [22], we screened several BCR-ABL+ human cell lines to determine which could generate leukemia in vivo and found that human BV173 cells, but not K562 cells, are capable of infiltrating into multiple hematopoietic organs and generating a lethal leukemia in NSG mice.