A2M is a protease inhibitor, meaning it inhibits an enzyme that promotes the breakdown of proteins. In the process of osteoarthritis, there are high concentrations of enzymes that promote the breakdown of the joint tissues. There are also low levels of A2M noted within osteoarthritic joints. By placing a high concentration of A2M in the joint, this degenerative process is halted, and A2M protects the joint from further degeneration. This treatment can be a stand-alone treatment, or can be combined with a stem cell treatment.