Single nucleotide polymorphisms (SNPs) in the CTLA4 and microsatellite polymorphism in FOXP3 gene region were also reported to be associated with several autoimmune diseases including, type-1 diabetes, systemic lupus erythematosus, autoimmune thyroid diseases and celiac disease [10]–[16]. This evidence concerns the gene CTLA4 and autoimmune thyroid disease.