In contrast to T. gondii, the ligand from uropathogenic E. coli (UPECs) that triggers innate responses through TLR11 in the urogenital tract has remained uncharacterized (Zhang et al., 2004). Our initial efforts in purifying this ligand suggested that it was a protein component of UPEC, although we were not able to identify the specific molecule recognized by TLR11 (Zhang et al., 2004). Given that PAMPs are rarely restricted to specific pathogens (Kawai and Akira, 2010), we chose to investigate the potential role of TLR11 in recognizing other pathogens in order to identify another source from which we could potentially purify the bacterial ligand for TLR11. Consistent with TLR11 mediating the innate response to UPECs at the urogenital epithelium, we noted that TLR11 is also highly expressed in the intestinal epithelium. This led us to speculate that TLR11 might also function in the recognition of enteropathogenic bacteria.