Although the role of TSLP in RA inflammation has not been elucidated, higher levels of serum TSLP in patients with imminent relapse could be important not only as a predictor of relapse, but also as a factor related to RA pathogenesis; pathological process from deep remission to relapse could be reminiscent of the process from healthy status to the onset of RA. Here, TSLP is linked to rheumatoid arthritis.