Contribution of IL-4 and IL-13 signaling to induction of common M2 marker genes during Taenia crassiceps infection. Fold induction of the genes in peritoneal macrophages from Taenia crassiceps–infected, IL-4–deficient (IL-4 KO) or IL-4Rα–deficient (IL-4Ra KO) BALB/c mice 32 days after infection compared with noninfected mice, expressed as percentage of the fold induction in wild-type mice. Gene expression was determined by reverse transcription followed by real-time quantitative PCR and was normalized for the housekeeping gene ribosomal protein S12. Values indicate the mean of at least 3 mice in each condition. Error bars indicate SEM. Data are shown for 1 representative experiment. *Significantly lower than in infected wild-type mice (P < .05).