Among subjects submitted to RET analysis in our laboratory, 117/163 (71.8%) had personal and/or family history of MTC (114) or CCH (3), while the remaining had personal and/or family history of other pathologies possibly related to RET alterations (PCC, PHPT, intestinal ganglioneuromatosis). The gene discussed is RET; the disease is medullary thyroid gland carcinoma.