The Hageman factor, also known as Factor XII, is a protein expressed in the liver that plays a crucial role in the coagulation cascade. It is responsible for initiating the intrinsic pathway that ultimately leads to the formation of a blood clot. There are several synonyms for the Hageman factor, including coagulation factor XII, F12, plasma thromboplastin antecedent, and contact factor. These synonyms are often used interchangeably in scientific literature and medical research, and they all refer to the same protein that is essential for maintaining the integrity of the vascular system and preventing excessive bleeding. Understanding the various synonyms for the Hageman factor is essential for scientists and medical professionals alike.