Index tumours larger than 20mm have been associated with increased disease-specific mortality.17 Higher calcitonin levels have been correlated previously with larger index tumours and more nodal metastases.10 The Pearson correlation coefficient showed a statistically significant positive correlation between the index tumour size and the preoperative calcitonin level (R=0.70; p<0.01). The gene discussed is CALCA; the disease is neoplasm.