In addition, the potent and highly selective BCL2 inhibitor ABT-199 (venetoclax), approved for chronic lymphocytic and acute myeloid leukemias, effectively reduced the frequency of murine CML LSCs and induced apoptosis in CML patient samples in combination with TKI-mediated BCR-ABL1 inhibition, and this drug combination was also effective in leukemia stem cells from blast crisis CML patients56. This evidence concerns the gene ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive.