Cells treated with HB22.7 followed by bortezomib demonstrate increased cytotoxicity. A. Ramos or Granta-519 cells were treated overnight with either bortezomib (Bz) (75 nM) or HB22.7 (60 μg/ml) alone (1]), bortezomib and HB22.7 concurrently (2]), bortezomib six hours prior to overnight treatment with HB22.7 (3]), or HB22.7 six hours prior to bortezomib overnight treatment (4]). B. Viability of Ramos (black bars) or Granta-519 (white bars) were measured spectrophotometrically utilizing the dye WST-1 and is expressed as % control (untreated) cells. Treatments are listed on the X-axis. Error bars = SEM. (*) = p-value < 0.05 against all other treatment groups (n = 3).