The metalloprotease GelE, produced by Enterococcus faecalis, degrades E-cadherin leading to loss of barrier function that is evident before inflammation in a mouse model of spontaneous colitis.131 Tight junctions are also targets of infectious agents such as Pseudomonas aeruginosa (through LasB),132H. pylori (PqqE and HtrA),61–63C. jejuni (HtrA), 79,80V. cholerae (vibrolysin),10,83Shigella, Salmonella or pathogenic Escherichia coli (SepA).72,133 Thus, microbes use proteases for host invasion with important implications in the gut. The gene discussed is HTRA1; the disease is colitis.