Considering that cytokines, chemokine, and immunomodulatory molecules play an important role in the pathogenesis of many diseases, including Chagas disease, and gene polymorphisms may influence the expression of these molecules, different studies have reported the association between different clinical forms of Chagas disease and polymorphisms at TNF [57–61], IL-1β [62], IL-10 [63], IL-4 [64], INF-γ [65], TGF-β1 [66], IL-12B [67], CXCL9 [68], CXCL10 [68], CCR5 [68–70], CCL2 [71], and CTLA-4 [25] genes. Here, CTLA4 is linked to Chagas disease.