According to prior studies on the association the CTLA4 gene with the development of various autoimmune diseases, the exon 1 +49 A/G polymorphism in CTLA4 exon 1 has been reported to be involved in the development of autoimmune diseases including Graves’ disease [28] and Hashimoto thyroiditis [27]. The gene discussed is CTLA4; the disease is autoimmune disease.