TNF and rheumatoid arthritis: Most importantly, the average relative gene expression level of TNFRSF1B was significantly lower in RA patients with rs3397 (CT: 0.34 ± 0.14 or TT: 0.27 ± 0.12) compared to RA patients with the major genotype (CC: 0.51 ± 0.17) (p-value < 0.05), as shown in Figure 2C. On the other hand, rs767455 did not have any significant effect on TNFRSF1A expression, as shown in Figure 2B, and the effect of rs1800629 on TNFα expression was not significant, as shown in Figure 2A.