Therefore, these patients with Graves’ disease could be divided into two groups: a homogeneous group, with TSAbs that recognized only the N-terminal region of the TSHR ectodomain and did not activate the chimeric receptors, and a heterogeneous group, with TSAbs that interacted with the C-terminal region of the TSHR ectodomain and activated the chimeric receptors. This evidence concerns the gene TSHR and Graves disease.