Death receptor 3 (DR3), a member of the tumor necrosis factor receptor (TNFR) superfamily, has been implicated in regulating T helper type 1 (TH)1, TH2 and TH17 responses as well as regulatory T cell and innate lymphoid cell functions during immune-mediated diseases. However, the role of TL1A/DR3 system in modulating the function of other lymphocyte subsets, such as TH9, in CD is not fully understood. In this work, we investigated whether TL1A/DR3 signaling regulates chronic intestinal inflammation by promoting intestinal TH9 cell differentiation.