👉 The term "antifibrinolysin" is a medical term that refers to an enzyme that breaks down fibrin, a protein found in blood clots. It is involved in the regulation of blood clotting and can be found in various organs such as the liver, spleen, and bone marrow. Antifibrinolysin plays a critical role in the body's immune response by breaking down fibrinogen, which is a precursor to thrombin, a protein that causes