Thyroid microsomal antibodies, namely, anti-TPO antibody, is a thyroid autoantibody targeting thyroid peroxidases [11] and is considered diagnostic of both Grave's disease and Hashimoto's thyroiditis, while in Hashimoto's thyroiditis, anti-TPO antibody is reported in approximately 90% of patients [12]. The gene discussed is TPO; the disease is Hashimoto thyroiditis.