To most well-informed scientists who do not work on bone,the idea that bone:determine anything other than your posture and location for the miseries of arthritis would come as quite a surprise.It would be like imagining that the walls of our home played something more than a passive role in the complexities of the lives conducted within.Yet something precisely as radical as that is what Karsenty and his colleague;boldly imagined,and then provocatively established in a series of studies over the pasl decade.Osteocalcin (OCN) is a vitamin Kdependent peptide hormone secreted by the bone-forming osteoblasts.