Abstract: This invention relates to nucleic acids derived from osteoarthritis (OA) tissue as well as compounds and compositions made using these nucleic acids. A variety of nucleic acid and polypeptide compounds and compositions are described and specifically disclosed. The nucleic acids or polypeptides may be contained within vectors or host cells and then used to produce agents such as nucleic acids, polypeptides, fragments of polypeptides, antibodies, and variants of each. These molecules can be used to diagnose or treat osteoarthritis, or to analyze the disease-modifying activity of OA drugs. Cells containing one or more nucleic acids or polypeptides of the invention can also be used as targets in high-throughput screening methods, particularly in screening for compounds designed to identify compositions affecting osteoarthritis.