IL4 and systemic sclerosis: Moreover, inhibition of mTOR by rapamycin significantly reduced the expression of pro-inflammatory cytokines and fibrogenic mediators including IL-4, IL-6, IL-17, and TGF-β, which finally resulted in attenuated skin fibrosis in both TSK/+ and bleomycin-induced SSc model mice, suggesting a pivotal role of mTOR signaling in promoting fibrosis development [134].