AITDs are multifactorial diseases in which autoimmunity plays a fundamental role with infiltration of the gland by T- and B-cells and production of specific autoantibodies, reactive to thyroid antigens [antithyroglobulin, anti-thyroid peroxidase (TPOAb), and anti-TSH receptor (TRAb)] [12]. The gene discussed is TPO; the disease is Autoimmunity.