C4b-binding protein: The good, the bad and the deadly. Novel functions of an old friend.
C4b-binding protein (C4BP) is best known as a potent soluble inhibitor of the classical and lectin pathways of the complement system. This large 500kDa multimeric plasma glycoprotein is expressed mainly in the liver but also in lung and pancreas. It consists of several identical 75kDa α-chains and often also one 40kDa β-chain, both of which are mainly composed of complement control protein (CCP) d
