Cell biology of the osteoclast G.David Roodman  Experimental Hematology  Volume 27, Issue 8, Pages 1229-1241 (August 1999) DOI: 10.1016/S0301-472X(99)00061-2

Figure 1 Bone biopsy specimen depicting an osteoclast in a resorption lacuna. Note the intimate contact between cells in the bone microenvironment and the osteoclasts (original magnification × 100) Experimental Hematology 1999 27, 1229-1241DOI: (10.1016/S0301-472X(99)00061-2)

Figure 2 Role of RANK ligand in osteoclastogenesis. Osteotropic factors induce upregulation of RANK ligand on marrow stromal cells and osteoblasts. RANK ligand then binds the RANK receptor on osteoclast precursors and induces osteoclast formation Experimental Hematology 1999 27, 1229-1241DOI: (10.1016/S0301-472X(99)00061-2)

Figure 3 Model for regulation of osteoclast formation. Stimulatory factors (+) such as the colony stimulatory factors (CSF), interleukin-6 (IL-6), transforming growth factor alpha (TGFα), or tumor necrosis factor (TNF) induce proliferation of osteoclast precursors. Factors such as 1,25-(OH)2D3 (1,25D) or parathyroid hormone (PTH) act as fusigens. Inhibitory factors (−) such as transforming growth factor beta (TGFβ) act on several stages of osteoclast formation. In contrast, interferon gamma (γIFN) and calcitonin (CT) appear to block the later stages of osteoclast formation Experimental Hematology 1999 27, 1229-1241DOI: (10.1016/S0301-472X(99)00061-2)