Considering that ZFX silencing inhibited the growth of CML cells, our data indicated that ZFX facilitates leukemogenesis induced by BCR/ABL similar to its role in other tumor models induced by different oncoproteins, such as Hedgehog or MLL–AF9 [8, 16]. This evidence concerns the gene BCR and chronic myelogenous leukemia, BCR-ABL1 positive.