CXCL8 and rheumatoid arthritis: To determine the role of DIM on main pro-inflammatory cytokines expression, the mRNA levels of IL-6, IL-8, IL-1β, IL-17, Receptor Activator of Nuclear Factor-κ B Ligand (RANKL) and special Osteoprotegerin(OPG) stimulating by TNF-α in RA-FLSs were measured with quantitative PCR after treated with 25 and 50 μM DIM for 24 h.