{"type":"root","children":[{"type":"paragraph","children":[{"type":"text","value":"Complement component 3, often simply called C3, is a protein of the immune system. It plays a central role in the complement system and contributes to innate immunity. C3 supports the activation of all the three pathways of complement activation i.e. the classical, alternative, and lectin pathways. Among the complement proteins, it is probably the most versatile and multifunctional molecule identified to date, having evolved structural features that allow it to interact in a specific manner with at least 25 different proteins. C3c is one of many proteolytic products of C3 activation and degradation."}]}]}