However, MR analyses found no significant causal associations between total iron-binding capacity (OR = 1.0, 95% CI: 0.999–1.002;p = 0.592) or transferrin saturation percentage (OR = 0.998, 95% CI: 0.996–1.000;p = 0.080) and risk of developing RA. This evidence concerns the gene TF and rheumatoid arthritis.