Recent studies have shown that cytokines produced by T lymphocytes and antigen presenting cells play an important role in both the induction and perpetuation of chronic intestinal inflammation.1-5 In particular, the balance between interleukin 12/interferon γ and transforming growth factor β (TGF-β) responses has been shown to regulate the occurrence of chronic intestinal inflammation.6 The TGF-β superfamily consists of multifunctional cytokines, including TGF-β 1–3, activins, inhibins, and bone morphogenetic proteins. TGF-β1 mediates its functions by binding to the accessory TGF-β type III receptor that serves as a ligand for the TGF-β type II receptor. Receptor bound TGF-β1 recruits TGF-β type I receptor into the complex leading to formation of a heteromeric complex that finally results in phosphorylation and activation of receptor …