There is a wide and diverse spectrum of diseases that involves the development of inflammation of the intestinal mucosa. Such diseases include inflammatory bowel disease that is, Crohn's disease and ulcerative colitis, necrotizing enterocolitis (which is a leading cause of death and disability in newborn infants) and a variety of infectious causes of intestinal dysfunction, due to enteroinvasive organisms such as Salmonella and Escherichia coli. As shown in Figure 1 , signaling via TLRs could lead to the development of intestinal inflammation through direct interaction of TLRs with the intestinal epithelium, or through effects on sub-epithelial and circulating leukocytes whose activation then leads to the initiation and propagation of mucosal inflammation. Although evidence exists to support this latter possibility, the expression of various TLRs in enterocytes (Table 3) suggests the possibility that direct interaction of intestinal TLRs with cognate ligands (see Table 1 ) may occur. Enteric bacteria in general, and LPS in particular, have been shown to play a critical role in the development of many diseases of intestinal inflammation (69) (70) (71) (72) , further suggesting the possibility that enterocyte TLR signaling may contribute directly to the development of these diseases.