A model for the mechanism of ADAM-9–mediated IL-6 production by osteoblasts in multiple myeloma. Myeloma cells (MC) express ADAM-9, which interacts directly with α_vβ₅ integrin on osteoblasts to induce IL-6 production via the p38 MAPK and cPLA₂ pathways. Myeloma cells also regulate IL-6 production in osteoblasts via alternative mediators through JAK2 and NF-κB pathways. CAM indicates cell adhesion molecules.