Because of the high frequency of hereditary MTC, even among presumed sporadic cases, genetic testing for pathogenic germline variants in the RET protooncogene associated with multiple endocrine neoplasia type 2 syndrome (MEN2) should be offered to all MTC patients according to the American Thyroid Association 2015 guidelines [1]. The gene discussed is RET; the disease is medullary thyroid gland carcinoma.