Mechanisms of BCR-ABL activity in CML and blast crisis, leading to stimulation of proliferation and to induction of genetic instability, DNA damage, and impaired DNA repair. Reactive oxygen species induced by BCR-ABL are thought to mediate DNA damage and genetic instability. Data are from Skorski,³⁴  Melo and Barnes,³¹  Radich,³²  and Perrotti et al.³³