TPO and thyroiditis: Thyroiditis stands for the presence of autoimmune chronic Hashimoto’s thyroiditis caused by antibodies against thyroid, namely anti-thyroperoxidase antibodies (antiTPO) or anti-thyroglobulin antibodies (antiTg) usually causing hypothyroidism or, at the other end of the same autoimmune spectrum, Graves–Basedow’s disease (with or without thyroid eye disease) due to serum thyroid-activating antibodies TRAb [143,144,145].