C-reactive protein (CRP) belongs to the proteins of the acute phase of inflammation. The name "C-reactive" comes from its ability to bind pneumococcal C-polysaccharide in the presence of calcium ions. The synthesis of C-reactive protein occurs in the liver, and the half-life is 12-24 hours (on average, 18 hours). C-reactive protein stimulates immune responses, phagocytosis, and activates the classical complement system.