The role of β3-integrins in tumor angiogenesis: context is everything

► αvβ3-Integrin antagonists function differently depending on the matrix to which cells are bound. ► The achieved dose of αvβ3-integrin antagonist dictates the angiogenic response. ► Cell-type-specific expression of αvβ3-integrin determines its role in tumor angiogenesis. ► αvβ3-integrin interacts with a large array of other proteins and these interactions may vary its angiogenic function.