This was evidenced by the detection of elevated levels of serum IgG1 in MyD88 knockout (305±40 μg/ml) and C57BL/6 mice (260±35 μg/ml) after H. polygyrus infection (2 weeks post-infection) (P>0.05), comparing to 180±20 μg/ml and 140±30 μg/ml in un-infected MyD88 knockout and C57BL/6 mice, respectively. The gene discussed is MYD88; the disease is infection.