Definition: Sclererythrin is a type of protein found in the blood. It's called this because it helps to protect the body from harmful substances that can cause bleeding, such as iron or lead. When you have a blood clot, your immune system (which protects your body) tries to dissolve the clot and stop further damage to the blood vessels. Sclererythrin is also involved in other processes like regulating blood pressure, maintaining blood flow to important organs, and preventing infections.