This image depicts a blood vessel containing a single red blood cell (RBC), and another RBC which is in the process of squeezing out of the blood vessel into the adjacent heart tissue. This leak of blood cells and serum proteins, called edema, damages the normally densely packed heart tissue by physically disrupting structures and also inducing an inflammatory response. Cheresh, Weis, and colleagues at The Scripps Research Institute have demonstrated the adverse effects of this edema in the heart tissue following a heart attack, and show that this leak can be prevented by the administration of drugs to block the activity of Src kinases shortly after the heart attack occurs.