C-reactive protein (CRP) belongs to the pentaxin family. CRP is a secreted protein found in plasma. It can binds two calcium ions per subunit.CRP can promotes phagocytosis, bacterial capsular swelling, complement fixation and agglutination through its calcium-dependent binding to phosphorylcholine which expressed on the surface of dead or dying cells. It can activate the complement system via the C1Q complex. CRP can interact with DNA and histones. In addition, CRP may scavenge nuclear material released from damaged circulating cells.