NOD1 and colitis: Previous studies have shown that the lack of either Nod1 or Nod2 had no effect on the extent of Salmonella-triggered intestinal inflammation whereas Salmonella caused reduced colitis in a Nod1/Nod2 double-knockout (DKO) or in a Rip2−/− mouse [5], which is the signaling molecule downstream of Nod1 and Nod2.