Factor XII is a protein in the blood that plays a crucial role in the coagulation process, which helps stop bleeding. It is part of the intrinsic pathway of blood clotting, activating other factors that lead to the formation of a clot. When blood vessels are injured, Factor XII is activated and initiates a cascade of reactions that ultimately result in the stabilization of a blood clot. Deficiencies or abnormalities in Factor XII can lead to bleeding disorders, although interestingly, individuals with low levels often do not experience excessive bleeding. Research into Factor XII also explores its potential role in inflammation and other physiological processes beyond coagulation.