S100A8 and rheumatoid arthritis: The levels of serum S100A8/9 (mean 5.99 ± 0.88 μg/mL vs. 1.92 ± 1.16 μg/mL; P < 0.0001) and S100A12 (mean 0.30 ± 0.04 μg/mL vs. 0.13 ± 0.11 μg/mL; P < 0.0001) were significantly higher in patients with recent-onset RA compared with healthy controls, and these levels essentially normalised after three months of treatment (mean S100A8/9: 5.99 ± 0.88 μg/mL to 2.49 ± 0.21 μg/mL; P < 0.0001; mean S100A12: 0.30 ± 0.04 μg/mL to 0.13 ± 0.01 μg/mL; P < 0.0001) (Figure 2).