The discovery that MMP14 titrates the response to PTH and bone anabolism in vivo, contributes new insights into the mechanism of adjusting PTH control of osteogenesis and bone homeostasis, and has significance for understanding bone metabolism with implications for the development of treatments for bone-wasting diseases such as osteoporosis and in overcoming the side effects of teriparatide (PTH 1–34). The gene discussed is PTH; the disease is osteoporosis.