CD68 and rheumatoid arthritis: The percentage of AIF-1-positive WBCs in patients with RA and OA was 1.35 ± 0.81% and 0.71 ± 0.25% (p < 0.01), respectively, whereas the percentage of AIF-1/CD68 cells in the SMs was 24.05 ± 7.17% and 4.78 ± 1.52% (p < 0.0001), respectively (Figure 1).