It was called ‘complement’ because it aided the antibacterial activity of antibodies. However, it is now known that the complement system can be activated early in an infection without the presence of ...

A complement C4 (also known as a complement component 4, or simply C4) is a test to measure the level of C4 proteins you have in your blood. These proteins play a role in how your immune system ...

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 ...