TLR4 and inflammatory bowel disease: Given that S100A9 functions as a ligand for TLR4 [68], and that TLR4 and CHI3L1 signaling pathways are interconnected in inflammatory bowel diseases [69], the ability of Fh15 to suppress both S100A9 and CHI3L1 suggests that it may also modulate additional molecules involved in these associated signaling pathways.