Your complement system consists of a group of important proteins in your bloodstream. These proteins help your immune system fight off harmful invaders, such as bacteria, and other foreign substances.

Complement component 3, often called C3, is an essential protein of the immune system. This protein plays a vital role in the body’s innate immune system, providing: the first line of defense against ...

University of Pennsylvania researchers have found a promising new treatment for periodontitis using a component of the immune system called complement, according to a new study in the Journal of ...

Among people with sickle cell disease—an inherited blood disorder—acute chest syndrome (ACS) is the leading cause of death. The condition is the result of red blood cells becoming stiff, sticky, and ...