TLR4 and Crohn ileitis: Likewise, we recently reported that oral administration of the TLR4 agonist lipid-A aggravated immunopathology in a murine model of Toxoplasma gondii-induced ileitis [11], and that genetic deletion of TLR4, or treatment with the LPS scavenger polymyxin-B, ameliorated disease symptoms in this model [12].