Figure 2 Significant correlation between interleukin (IL)7 and tumour necrosis factor α (TNFα) levels in the synovial fluid (SF) and synovial tissue of patients with rheumatoid arthritis (RA). Table 1 shows the characteristics of the patients with RA. (A) In RA, SF (n = 30) levels of IL7 and TNFα levels were measured using ELISA. (B) Numbers of IL7 cells (average of the number cells/mm² tissue area) and TNFα expression levels (optical density (OD)) in synovial tissue of patients with RA (n = 22, one missing value) were assessed immunohistologically. Spearman's correlation coefficient r and p value are given.