Prognosis of MTC is relatively good with a 10-year survival rate ranging from 47% to 78%2,3 and even better in patients with CT doubling-time of more than 2 years.4 Within the past decade the prognosis has improved mainly because of earlier diagnosis and improvement in surgical procedures.5,6 Nevertheless, more than 50% of nonprophylactic thyroidectomized patients are not cured after surgery.5 In these cases residual tumour cells can be detected by measuring serum calcitonin alone or in combination with pentagastrin stimulation. The gene discussed is CALCA; the disease is neoplasm.