Effect of PF-4–derived peptides on binding of¹²⁵I-VEGF to CHOmVEGFR2 cells. CHOmVEGFR2 cells are incubated with 5 ng/mL ¹²⁵I-VEGF with or without 500 ng/mL unlabeled ligand (NS) or PF-4–derived peptides in the presence of 100 ng/mL heparin. Binding experiments are performed as indicated in Materials and Methods. Peptide 47-70 (▴), 34-58 (▪); 17-58 (⧫), 47-58 (□). Results are expressed as the mean ± SD of experiments done in duplicates.