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 ...

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 ...

Global understanding of complement has shifted and developed since the 21st century: from our idea of a blood-based antibiotic system to a global regulator of immunity and tissue homeostasis. Recent ...

This story was updated on February 5, 2019. Just when you thought ApoE biology couldn’t get any more complicated, scientists have discovered a new function for this apolipoprotein. According to a ...

Current treatment methods for C3 glomerulopathy (C3G) help support kidney function and suppress immune system activity. Emerging therapies interrupt the proteins responsible for disease activity. C3G ...

These findings suggest complement protein levels may be an important biomarker for type 1 diabetes. Disruption of the complement system appears to precede the onset of islet autoimmunity (IA), making ...