Due to dysregulated expression of tumor necrosis factor (Tnf), TNFΔARE mice develop a CD-like ileitis that is dependent on microbial composition and characterized by diminished expression of PC-derived AMPs (Schaubeck et al., 2016) and impaired mitochondrial function in the ISC niche (Khaloian et al., 2020). Here, TNF is linked to Crohn ileitis.