Effect of VLDL receptor antibody on TFPIc23 antiproliferative activity. Quiescent HUVECs were preincubated for 2 hours at 37°C with a VLDL receptor-specific polyclonal antibody (R4522; ○) or an equal volume of buffer (•). After incubation, 10 ng/mL bFGF was added with increasing concentrations of the TFPIc23 peptide. Cell proliferation was assessed 48 hours later by measuring BrdU incorporation in triplicate wells. Data are presented as means ± SEM.