Induction of apoptosis in SKW6.4 lymphoma cells by combinations of lumiliximab, rituximab, and fludarabine. (A) SKW6.4 cells or (B) CLL cells were incubated in the presence of lumiliximab, rituximab, or both followed by crosslinking with F(ab′)2 goat antihuman IgG, as described in “Cell treatment.” Percentage apoptosis was determined after 18 hours using the caspase-3 flow cytometry–based assay as described in “Apoptosis assays.” (C) SKW6.4 cells or (D) CLL cells were incubated in the presence of lumiliximab, fludarabine, or both, as described in “Cell treatment.” Percent apoptosis was determined after 18 hours, as described in “Apoptosis assays.” In panels A and C, each error bar represents SD.