Once fibroblasts and ECs express the proper integrin receptors, they invade the fibrin/fibronectin-rich clot in the wound space and start synthesizing a permanent ECM [reviewed in [131]].It is important to recognize that angiogenesis is a complex process, in which ECs are stimulated by growth factors, such as VEGF or FGF-2, to proliferate and migrate into the ECM to form new capillaries.