1) They can be used to replace lost or diseased cartilage in the joints. Stem cells can regenerate a healthy joint through actual tissue growth. 2) They can tamp down the overactive immune system and inflammation, at least in part responsible for joint destruction, swelling, and pain. This is termed immunomodulation, as stem cells have immune modulating functions. These powerful anti-inflammatory factors are 20x more concentrated than those factors seen in Platelet-Rich Plasma (PRP).