- Proteomic analysis of articular cartilage shows increased type II collagen synthesis in osteoarthritis and expression of inhibin betaA (activin A), a regulatory molecule for chondrocytes. Hermansson, M., Sawaji, Y., Bolton, M., Alexander, S., Wallace, A., Begum, S., Wait, R., Saklatvala, J. J. Biol. Chem. (2004)