INTRODUCTIONrnAdult bone is a dynamic tissue that constantly adapts its structure through bone remodeling. Osteocytes originate from osteoprogeni-tors through osteoblast differentiation and are the most abundant bone cells. It is now widely believed that osteocytes play key roles in the regulation of bone remodeling and in the mediation of bone mechanotransduction, although the mechanisms are currently incompletely defined.1-10 Elucidating these mechanisms will advance the progress of bone biology research and help define new targets for the treatment of metabolic bone diseases.