Using a different model, mice that lacked IL-1 receptor antagonist (IL-1Ra), which spontaneously develops autoimmune arthritis, Osada and coworkers [17] showed that infected mice with S. mansoni had lower arthritis scores, less severe histopathology, lower production of TNF-α and IL-17, and higher production of IL-4 and IL-10. Here, IL4 is linked to arthritic joint disease.