COMP and osteoarthritis: Studies on osteoarthritis in both humans [12,13,14,15,16,17,18] and horses [19,20,21,22,23,24,25,26,27,28] indicate that COMP may be a good marker for certain joint diseases, while the analysis of fragmentation patterns in joint synovial fluid suggested that COMP fragments were the most sensitive indicators of disease [17,18,19,25,28].