This includes Hashimoto thyroiditis that reduces aT; Graves' disease which increases Ab; Changing iodine supply which affects bTH, including iodine deficiency in which bTH is low; hypersecreting nodules which affect bTH and bT; etc. In all of these conditions, simultaneous measurements of T4 and TSH should fall on the same curve. The gene discussed is CD4; the disease is Hashimoto thyroiditis.