Historically significant events in the discovery of RANK/RANKL/OPG

Figure 1 Schematic representation of osteoblast involvement in hormone - stimulated bone resorption (reproduced with permission). OB: Osteoblast; PTH: Parathyroid hormone; PGE: Prostaglandin E.

Figure 2 Proposed participation of cells in the osteoblast lineage in the action of the bone - resorbing hormones (reproduced with permission from Ref. 39). PTH: Parathyroid hormone; PGE₂: Prostaglandin E₂; EGF: Epidermal growth factor.

Figure 3 Representation of the co-culture method that showed the contact-dependent promotion of osteoclast formation by stromal osteoblasts.

Figure 4 Concepts of regulation of osteoclastogenesis from the mid-1980’s until the discovery of the molecular regulation mechanisms. Three different signaling pathways converged to promote formation of osteoclasts through undefined mechanisms. IL: Interleukin; PTH: Parathyroid hormone; LIF: Leukemia inhibitory factor.