CD4 and helminthiasis: As Red5Cre is not specific to only ILC2 and can also target Th2 cell responses elicited by helminth infection, we assessed IL-5RFP expression in CD4+ T cells at day 7 after infection but observed at this time point over 95% of RFP+ cells were ILC2 (Fig. S4, B and C), while surface CD98 expression was unaffected on T cells in floxed animals (Fig. S4, D–G).