Although MTC is commonly expected in patients with elevated basal (bCtn) and stimulated (sCtn) serum calcitonin levels, the final diagnosis is based on the results of preoperative fine-needle aspiration cytology and/or postoperative histological tissue analysis of a thyroid nodule or lymph node (LN) [2]. The gene discussed is CALCA; the disease is medullary thyroid gland carcinoma.