Protein C is a protein in the blood that plays a crucial role in regulating blood clotting. It is produced in the liver and activated by a complex involving thrombomodulin and thrombin. Once activated, protein C helps to inactivate factor Va and factor VIIIa, which are essential for the clotting process. Deficiency in protein C can lead to an increased risk of abnormal blood clots, a condition known as thrombophilia. This can result in serious health issues, such as deep vein thrombosis or pulmonary embolism. Monitoring and managing protein C levels can be important for individuals with a history of clotting disorders.