<prompt> Aggrecan inReceptor over plateletsA molecule present in osteoid tissueGranules in leukocytesImportant component of cartilage  <response>: Aggrecan is the major proteoglycan component of cartilage. It is composed of several glycosaminoglycans hyaluronic acid, chondroitin sulfate and keratin sulfate and both link and core proteins. 