In RA there was no association between levels of circulating IL-7 and disease duration, inflammation as measured by CRP (Fig. 1b; nonsignificant correlation [R = 0.201, P = 0.161]), presence of a shared epitope (n = 17), or antirheumatic therapy (nonsteroidal anti-inflammatory drugs, methotrexate, or steroids). Here, CRP is linked to rheumatoid arthritis.