Plays a role in the structural integrity of cartilage via its interaction with other extracellular matrix proteins such as the collagens and fibronectin. Can mediate the interaction of chondrocytes with the cartilage extracellular matrix through interaction with cell surface integrin receptors (PubMed:16051604, PubMed:16542502). Could play a role in the pathogenesis of osteoarthritis (PubMed:16542502). Potent suppressor of apoptosis in both primary chondrocytes and transformed cells. Suppresses apoptosis by blocking the activation of caspase-3 and by inducing the IAP family of survival proteins (BIRC3, BIRC2, BIRC5 and XIAP) (PubMed:17993464). Essential for maintaining a vascular smooth muscle cells (VSMCs) contractile/differentiated phenotype under physiological and pathological stimuli. Maintains this phenotype of VSMCs by interacting with ITGA7 (By similarity). {ECO:0000250|UniProtKB:P35444, ECO:0000269|PubMed:16051604, ECO:0000269|PubMed:16542502, ECO:0000269|PubMed:17993464}. This is the function of COMP (cartilage oligomeric matrix protein, ENSG00000105664).