Osteocyte control of local bone environment. Osteocytes orchestrate bone resorption and bone deposition by controlling osteoclast and osteoblast activity. Osteocytes release RANKL (receptor activator of nuclear factor kappa-β ligand) to induce osteoclast differentiation, as well as OPG (osteoprotegerin) to downregulate osteoclastogenesis. Importantly, osteocytes also release FGF-23 (fibroblast growth factor-23), BMPs (bone morphogenetic proteins), and sclerostin to regulate osteoblast activity. Denosumab and sclerostin antibody are two antibodies that interact with bone cell biology to increase bone mass.