IL-1, VEGF, macrophage inhibitory factor (MIP) 1α, TNF-α, receptor activator of nuclear factor-κB (RANK) ligand and osteoprotegerin are agents mediating the osteoclastic activity that brings about the myeloma-associated osteolytic bony lesions [1,6,10,18]. The gene discussed is TNFRSF11B; the disease is plasma cell myeloma.