Furthermore, Schurch et al. 25 showed that transfer of activated leukemia-specific effector cytotoxic T cells into a mice model of CML induced the proliferation of leukemic stem cells through IFNγ secretion, while IFNγ treatment in vitro increased the proliferation and colony formation of primary human CD34+ CML stem/progenitor cells. This evidence concerns the gene CD34 and chronic myelogenous leukemia, BCR-ABL1 positive.