Since IL-22 is known to be involved in protection of hepatocytes during hepatitis24, we here used the reticulotropic T. cruzi strain Tulahuen that mainly infects spleen and liver cells and induces splenomegaly and liver pathology27, 28, 29, 30, 31 to analyze the role of this cytokine for protection and/or pathology during experimental Chagas disease. The gene discussed is IL22; the disease is Chagas disease.