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 ...

However, the discovery that receptors for complement activation fragments are expressed by almost all immune cells — including B cells and T cells — and that these cells can sense and convert the ...

The mammalian immune system is a remarkable complex of biochemical processes enabling efficient detection and prosecution of pathogens that threaten host viability. The incredible complexity 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 ...