In comparison with the CD34-positive fraction, which is considered to contain a large number of leukemic stem cells (LSCs), CD34-positive cells derived from CML patients had a higher expression of the autophagy-related gene ATG4B than normal bone marrow CD34-positive cells, and ATG4B knockdown reduced cell proliferative capacity and colony-forming ability [47]. This evidence concerns the gene ATG4B and chronic myelogenous leukemia, BCR-ABL1 positive.