Together, these findings suggest that DS, particularly in combination with Cu, acts to induce cell death of adult B-ALL cells primarily via activation of the intrinsic apoptotic pathway, at least in part, due to down-regulation of anti-apoptotic Bcl-2 family proteins (e.g., Bcl-2 and Bxl-xL). This evidence concerns the gene BCL2 and precursor B-cell acute lymphoblastic leukemia.