Arthritis is a widespread, debilitating disease in which the joint cartilage slowly disintegrates. One of the possible remedies for this disease is to regenerate cartilage and transplant the regenerated tissue to the affected joint. To regenerate cartilage, we need to have a thorough understanding of the mechanisms of how cartilage is formed from progenitor cells. Many of the signaling events in the regeneration process are similar to tissue formation processes in the embryo. Dr. Zeng’s long-range goal is to reveal the mechanisms that control cartilage formation in the embryo to provide knowledge for treating arthritis through cartilage regeneration.