Protein C is a naturally occurring anticoagulant protein that is synthesized in the liver and is a key protein in the regulation of blood clotting. However, there are several synonyms that refer to protein C. These synonyms include plasma thromboplastin antecedent, vitamin K-dependent protein C, coagulation factor XIV, and PROC. These terms are often used interchangeably and refer to the same protein that is essential in ensuring healthy blood clotting and preventing excessive bleeding. Whether one refers to protein C, plasma thromboplastin antecedent, or any of the other synonyms, it is clear that this protein plays an important role in maintaining the overall health of our body's circulatory system.