Illustration of antibodies (blue) targeting fibrinogen (purple) that is leaking from a damaged blood vessel (red) in the brain. Fibrinogen, also known as factor I, is a blood clotting glycoprotein. Dysfunction or break down of the blood-brain barrier allows fibrinogen to enter the brain, where it causes inflammation and leads to the death of neurons (nerve cells). This process is implicated in the early stages of a number of neurodegenerative diseases, including Alzheimers disease and multiple sclerosis (MS). Researchers have engineered a monoclonal antibody that blocks the damaging inflammatory and oxidative activity of fibrinogen, without affecting its clotting ability. It is hoped that his antibody will be able to treat neurodegenerative diseases as well as inflammatory conditions with vascular damage in other organs.