CCL2 and rheumatoid arthritis: IL-6 augmented production of chemokines such as monocyte chemotactic protein-1 (MCP-1) and IL-8 from endothelial cells, mononuclear cells, and RA-FLS, and also induced adhesion molecules such as ICAM-1 in endothelial cells and increased adhesion of monocytes to endothelial cells [23, 24].