Antiproliferative effects of hL243γ4P alone and in combination with rituximab. Effects of mAbs on proliferation of NHL cells lines were determined by MTS assays (A-B) and ³H-thymidine uptake assays. (C) Effect of combining hL243γ4P and rituximab on proliferation of cell lines. Cells were cultured with the mAbs with or without a second antibody for cross-linking. Error bars represent SD of triplicates. On the x-axis, hL243 refers to the γ4P form.