Chondroadherin is an approximately 36 kDa secreted glycosaminoglycan that contains nine tandem leucine-rich repeats as well as N-terminal and C-terminal leucine-rich domains. It is a component of the extracellular matrix in cartilage, tendon, bony growth plates, skeletal and cardiac muscle, lung, gastrointestinal tract, pancreas, cerebellum, and eye. It is cleaved by HTRA1/Omi during intervertebral disc degeneration. Chondroadherin functions as an adhesion protein by binding to Integrin alpha 2/beta 1, Collagen II, and Collagen VI. It also promotes complement activation through binding to C1q and Complement Factor H.