Cells treated with HB22.7 followed by bortezomib demonstrate increased apoptosis. Ramos cells were treated with bortezomib, HB22.7, or both (concurrently or sequentially) as described in Figure 1a and in Materials and Methods. Cells were stained with propidium iodide and apoptosis was assessed via flow cytometry by quantifying the sub-G1 (apoptotic) cell population. The percent of apoptotic cells is listed in the upper right corner of each panel. Results shown are representative of three separate experiments.