For example, in our tolerance induction study in murine experimental autoimmune thyroiditis (EAT), a model for the prevalent Hashimoto’s thyroiditis (14), co-injection of anti-CTLA-4 with the autoantigen, thyroglobulin (Tg), interfered with activation of naturally existing CD4+CD25+Foxp3+ Tregs (nTregs); the mice developed thyroiditis, mimicking a major clinical autoimmune sequela (15). This evidence concerns the gene CTLA4 and Hashimoto thyroiditis.