PROS1 and infection: Similar to the phenotype of OTULINIEC-KO mice, mice with intestinal epithelial deficiency in A20, a crucial ubiquitin-binding anti-inflammatory and cytoprotective protein that has been associated with IBD [40, 41], do not develop spontaneous intestinal pathology, but are also hypersensitive to TNF and DSS [18] and to infection with Salmonella [38].