Figure 5.

Angiogenesis. Illustration of the angiogenesis cascade that involves: (1) pericyte detachment and basal membrane degradation in response to endothelial cell activation; (2) migration of endothelial tip cells in the direction of the growth factor gradient; (3) provision of support of endothelial tip cells by the underlying stalk cells; (4) continuation of this process to form luminized vessel sprouts; (5) fusion of sprouts; and (6) formation of a functional vessel which is further stabilized by deposition of a basal membrane and attraction of pericytes for structural support [3]. Figure reproduced with permission from Reference [3]. BM, basal membrane; EC, endothelial cell.