These results indicate that proinflammatory cytokine TNFα can promote Th17 cell differentiation in active RA patients via enhancement of monocytes derived IL-6 and IL-1β production, and the signalling pathway is probably through TNFRI and TNFRII which are both expressed on the surface of monocytes. This evidence concerns the gene TNFRSF1A and rheumatoid arthritis.