Thus, we suggested that this CTLA-4-mediated suppression mechanism could be used by Treg cells only in IND, but not by CARD patients, since Chagas cardiomyopathy patients demonstrated a higher frequency of Treg CD28+ lymphocytes and not CTLA-4, as shown by IND patients in our previous studies (38). This evidence concerns the gene CTLA4 and Chagas cardiomyopathy.