Receptor Activator of Nuclear Factor Kappa B Ligand (RANKL) is a transmembrane protein produced by osteocytes and is part of the tumor necrosis factor (TNF) family. It is the main stimulant for osteoclast formation and is essential for their survival. RANKL expression leads to bone reabsorption and loss which is counteracted by osteoprotegerin (OPG). RANKL/OPG regulate bone remodeling and an imbalance may lead to bone metabolic diseases. Sample types: Mouse, Rat Cell Culture, Serum, Urine. Range: 125 - 4000 pg/mL, Sensitivity: 125 pg/mL