INTRODUCTIONrnDrugs for the treatment of skeletal disorders, such as osteoporosis, typically fall into one of two categories. These drugs function to either block bone resorption by osteoclasts or augment bone formation by osteoblasts. However, current treatment options still have strong limitations, due in part to both the few anabolic agents available and restrictions on the use of these agents.1-2 To continue to advance therapy for disorders of low bone mass, the identification of new strategies to promote bone formation is critical.