Although no significant differences in the amount of IFN-γ production per cell, as determined by MFI, were apparent between CD4+CTLA-4+ and CD4+CTLA-4− (Figure 1C) or CD4+LIR-1+ and CD4+LIR-1− (Figure 1D) T cells, irrespective of the clinical status, subjects with severe heart disease (G3 subjects) showed lower IFN-γ production in their T. cruzi antigen-responsive CD4+ T cells compared with those subjects without cardiac involvement (G0 subjects), (Figure 1C and Figure 1D). Here, CTLA4 is linked to heart disorder.