The role of IL-17 is also essential for protection against Trypanosoma cruzi in the acute phase of Chagas disease (61, 62), suggesting that Th17 cells are important in the successful clearance of kinestoplastid protozoans such as Leishmania. However, although Th17 cells and IL-17 have been shown to protect against some intracellular pathogens including Leishmania (63, 64), many recent findings point to them as being responsible for excessive inflammation and pathology (65, 66). This evidence concerns the gene IL17A and Chagas disease.