Figure 5 Proliferation assay: if the culture medium contains vascular endothelial growth factor (50 ng/ml), the gap in this wound scratch assay is almost closed by proliferated endothelial cells after 48 h (A, magnification ×20). If bevacizumab (0.5 mg/ml) is added to the assay, there is almost no proliferation into the gap, demonstrating the antiproliferative effect of bevacizumab (B).