GST-MDA-7/IL-24 down-regulates Mcl-1 and Bcl-xL and up-regulates Noxa and Bim in human leukemia cells. U937 (A), HL60 (B), MV4-11 (C) cells, or leukemic blasts (D) were exposed to GST-MDA-7/IL-24 for the designated intervals, after which Western blot analysis was performed. The GST-MDA7/IL-24 concentrations used were 200 nM for U937 cells and 100 nM for HL60, MV4-11, and leukemic blasts.