F2R and brain ischemia: As early as hours after brain ischemia, increased oxidative stress activates endothelial cells to a proinflammatory and prothrombotic state, and several proteins, such as protease activated receptor 1 (PAR-1), vascular cell adhesion molecule 1 (VCAM-1), and tissue factor (TF), are upregulated in the ischemic core and surrounding tissue [17-19].