IL1B and rheumatoid arthritis: Moreover, among the three groups, siRNA + BMSCs group showed the lowest expression of IL-1β, TNF-α and NF-κB-P65 mRNA (Figure 4D), suggesting that the combination of IL-1β/TNF-α siRNAs and BMSCs was able to inhibit the IL-1β, TNF-α and NF-κB-P65 expression in vivo and BMSCs, siRNA and siRNA + BMSCs showed beneficial effect on alleviating inflammation of RA.