Fibrin is a protein that plays a crucial role in the body's healing process. It is formed from another protein called fibrinogen, which is produced by the liver. When a blood vessel is injured, enzymes convert fibrinogen into fibrin, creating a mesh-like structure that helps to stop bleeding by forming a clot. This fibrin mesh not only helps to seal wounds but also provides a scaffold for platelets and other cells to gather and promote healing. Over time, the fibrin is gradually broken down by another protein called plasmin, allowing the tissue to heal and restore normal function.