In the presence of 0.1 ppm of Cd, addition of TNF led to a similar effect on cell viability to exposure with Cd at 1 ppm alone for both PVNS and RA synoviocytes (7.0 ± 0.9% and 8.6 ± 5.0% respectively, p = 0.031, Fig. 5). This evidence concerns the gene TNF and rheumatoid arthritis.