Resetting the clock on arthritis.

While many of intricacies of the mammalian circadian rhythm remain unknown, the role that this physiological clock plays in our everyday lives and within the global ecosystem is clearly evident. However, only recently has the importance of circadian rhythm in cartilage health and joint homeostasis been brought to light. A recent study by Hand and colleagues advances our understanding of these processes further by demonstrating that disruption of circadian clock regulation in mesenchymal cells not only has an impact on the development of joint structures, but on the inflammatory response and on the onset/pathogenesis of arthritis.