Figure 6: Role of MMPs in angiogenesis: Angiogenic factors such as VEGF and bFGF (colored triangles) secreted by inflammatory or tumor cells bind to their respective receptors (Y-shaped receptors) on the surface of endothelial cells. This activates the endothelial cells to secrete MMPs, to change their expression of integrins (T-shaped receptors), and to undergo proliferation. bFGF = Basic fibroblast growth factor (bFGF) and VEGF = Vascular endothelial growth factor