The effect of GST-D5 and mAb C11C1 on the proliferation of HCT-116 cells. HCT-116 cells were grown to 50% confluence and counted as outlined in “Materials and methods.” This count at 0 time was designated as 100%. Equal numbers of cells were added to media and treated at intervals as indicated with 500 nM recombinant proteins, GST (○) as control, GST-D5 (□), or 1 μM mAb C11C1 (•) as test proteins. Aliquots were counted at 24, 48, and 72 hours and expressed as mean ± SD (n = 3).