MTC, which accounts for 5-8% of all thyroid cancers, is mainly sporadic in nature, while a hereditary pattern (multiple endocrine neoplasia type 2 (MEN 2), transmitted as an autosomal-dominant trait due to germline mutations of the RET proto-oncogene, accounts for about 29% of cases [1]. The gene discussed is RET; the disease is multiple endocrine neoplasia type 2.