To test whether the enhanced production of IL-13 early during infection was responsible for expulsion of a chronic T. muris infective dose, we crossed the Itgb8 (CD11c-Cre) mice with C57BL/6 IL-4 knockout mice, which have previously been shown to lack the ability to generate an IL-4/13-mediated Th2 response during T. muris infection [26]. This evidence concerns the gene IL4 and infection.