Interestingly, overexpression of Ahi-1 alone in primitive hematopoietic cells confers a proliferative advantage in vitro and induces a lethal leukemia in vivo; these effects can be enhanced by BCR-ABL, a fusion oncoprotein that plays a major role in the genesis of CML [19]. This evidence concerns the gene BCR and chronic myelogenous leukemia, BCR-ABL1 positive.