CTLA4 and Hashimoto thyroiditis: The present study found higher frequency of +49AG, +49GG and CT60GG genotypes among autoimmune hypothyroidism patients and this seems to modulate CTLA4 mRNA expression (Fig 2A, 2B, 2C & 2D) however, +49AA, CT60AA and CT60AG genotype does not seem to modulate CTLA4 mRNA expression and hence patients harboring it may have other genetic factors involved in disease pathogenesis supporting the fact that being an autoimmune disease autoimmune hypothyroidism may have varied type of precipitating factors [21].