Furthermore, analysis of caspase activation (in Reh and PreB697 lines) demonstrated that re-expression of SLC22A15 was associated with rapid induction of caspases 3/7 (Fig. 3c) in the absence of alteration in the underlying rate of proliferation (Fig. 3d), suggesting that re-expression of SLC22A15 resulted in induction of cell death and thus functions to inhibit ALL cell survival in all ALL cytogenetic subgroups tested. This evidence concerns the gene SLC22A15 and acute lymphoblastic leukemia.