Fig. 1 A role for integrin αvβ3 in governing survival of angiogenic endothelial cells. Data from inhibitor studies and genetic investigations suggest that integrin αvβ3 (and likely other integrins) can function as a biosensor. When ligated by an immobilized matrix, they provide mechanical anchorage to the ECM, and trigger survival signals (left). When ligands are absent, or in the presence of (soluble) endogenous or therapeutic antagonists, the integrin activates a death pathway, leading to cell death (center) and suppressing angiogenesis (lower panels). However, when αvβ3 is absent, the ability to sense ECM and to trigger endothelial cell apoptosis through this integrin is lost (right), contributing to increased pathological angiogenesis (lower right).