The complement system is a critical modulator of immune responses that triages microbial and other threats through pattern recognition, tailored effector functions, and intensive crosstalk with other ...

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 ...

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 ...

When told what to kill, the complement system deftly deals the final blows—helping the immune system purge away pathogens and infected cells. But in the nervous system, debate rages as to whether this ...

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 ...