In contrast, CD4+ T cells from the synovial fluid of established RA patients showed an augmented secretion of IL-17 to the medium (6757, 3724–19800 pg/ml after a 16 h stimulation and 6933, 4128–11420 pg/ml after a 4-day stimulation), when compared with CD4+ T cells from the peripheral blood of eRA patients, established RA patients and controls (Fig. 1D). This evidence concerns the gene IL17A and rheumatoid arthritis.