suur, paljusid kondroitiin- ja kerataansulfaadi ahelaid sisaldav proteoglükaan, mis annab kõhredele võime vastu pidada välisele survele, Aggrecan (ACAN), also known as cartilage-specific proteoglycan core protein (CSPCP) or chondroitin sulfate proteoglycan 1, is a protein that in humans is encoded by the ACAN gene. This gene is a member of the lectican (chondroitin sulfate proteoglycan) family. The encoded protein is an integral part of the extracellular matrix in cartilagenous tissue and it withstands compression in cartilage.