CCR7 and rheumatoid arthritis: The frequencies of CD8+CCR7+ expressing cells in whole PBL of BDA patients (4.35 ± 2.75%, p = 0.0004) were significantly higher than those of RA patients (2.88 ± 2.20%, p = 0.0004), but not different to HC (5.73 ± 3.49%) (Figure 2E).