A preclinical study demonstrated that semaglutide and other GLP-1 RAs cause a dose-dependent and treatment-duration-dependent increase in thyroid C-cell hyperplasia, adenomas, and medullary thyroid carcinoma (MTC) in rats and mice, which is mediated by the GLP-1 receptors that are abundantly expressed on rodent C-cells [17]. The gene discussed is GLP1R; the disease is adenoma.