Figure 1.

Relative risk of anti-CP-positive RA with mineral exposure and different expression of SE genes. The relative risk (RR) of developing rheumatoid arthritis (RA) positive for antibodies to citrulline-containing peptides (anti-CP) with mineral exposure and shared epitope (SE) genes compared with unexposed subjects with SE genes is 1.4, with 95% confidence interval = 0.8–2.4. The corresponding risk among subjects with no SE gene is 1.5, with 95% confidence interval = 0.6–3.9.