Production of pro-inflammatory cytokines.TLR activation induces human mononuclear cells and primary myeloma cells to secrete pro-inflammatory cytokines including IL-3, IL-6, vascular endothelial growth factor, basic fibroblast growth factor, hepatocyte growth factor, macrophage inflammatory protein (MIP)-1α, and the receptor activator of NF-κB ligand (RANKL) [65]. Here, HGF is linked to plasma cell myeloma.