Navitoclax (ABT-263), an orally bioavailable small molecule with a binding profile similar to that of ABT-7379, also disrupts interactions involving BCL2 and BCLXL, causes BAX/BAK-dependent apoptosisin vitro, and induces complete regressions in xenograft models of small-cell lung cancer (SCLC) and acute lymphoblastic leukemia (ALL)9. This evidence concerns the gene BAK1 and acute lymphoblastic leukemia.