Tang J, et al. - Authors gauged the levels of serum interleukin-35 (IL-35) before and after treatment and its relationship with clinical parameters as well as the frequency of different subsets of CD4+ T cells in patients with systemic sclerosis (SSc) to explore the role of IL-35 in the pathogenesis of SSc. Findings suggested a positive association of the levels of serum IL-35 with IL-4 and it tended to be positively correlated with the frequency of Tregs in SSc patients. There was a probable association of the higher levels of serum IL-35 with the development of SSc and severity of pulmonary fibrosis in these patients.