Activated protein C is a protein in the blood that plays a crucial role in regulating blood clotting. It is formed from protein C, which is activated by the enzyme thrombin in the presence of thrombomodulin. Once activated, it helps to break down fibrin, a key component of blood clots, and inhibits other proteins that promote clotting. This process is essential for maintaining a balance between clot formation and breakdown, preventing excessive clotting that can lead to conditions like thrombosis. Additionally, activated protein C has anti-inflammatory properties, contributing to the body's overall response to injury and infection.