TRAb is an IgG antibody produced by thyroid B-infiltrating lymphocytes, and it is divided into 3 types based on different functions (35): (1) TSAb have a TSH-like effect and cause excessive secretion of TH after combination with TSHR; (2) Thyroid-stimulation blocking antibody (TSBAb) combines with TSHR to block the function of TSH, which leads to reduced secretion of TH; and (3) TGI stimulates goiter but has no effect on thyroid function. The gene discussed is TSHR; the disease is goiter.