Receptor activator of nuclear factor-κB ligand（RANKL）-receptor activator of nuclear factor-κB（RANK）and osteoprotegerin（OPG） discovered in the mid 1990s is the key signaling system for the regulation of bone resorption.
RANKL-RANK signaling regulates osteoclast formation, activation and survival in normal bone modeling and remodeling and increases bone resorption in a variety of pathologic conditions. OPG protects bone from excessive resorption by binding to RANKL and preventing it from binding to RANK. This article reviewed regulation of RANKL-RANK-OPG in bone modeling and remodeling.
