To sense or not to sense, Paneth cell regulation of mucosal immunity.

Paneth cells located within intestinal crypts support epithelial stem cells and immunity through growth factors and antimicrobial peptides. In this issue of Cell Host & Microbe, Wallaeys et al. report that TNF sensing by Paneth cells disrupts the unfolded protein response and decreases antimicrobial peptides, causing bacterial translocation and sepsis.