Cover figure courtesy of Motta et al, "High Molecular Weight Kininogen Regulates Prekallikrein Assembly and Activation on Endothelial Cells: A Novel Mechanism for Contact Activation." The graphic schematizes that once the kininogen-prekallikrein complex binds to endothelial cells, a membrane protease activates prekallikrein leading sequentially to tissue plasminogen activator liberation, single chain urokinase activation, and fibrinolysis.