Pentagastrin stimulation test:The mean peak pentagastrin-stimulated CT level was 46.77 ± 34.14 pg/mL (10-142 pg/mL) in benign nodular goiter group, 459.10 ± 494.37 pg/mL (108 - 1938 pg/mL) in MTC group, 195 ± 51.39 pg/mL (117 - 274 pg/mL) in CHH group and 67.36 ± 47.04 pg/mL (14 - 149 pg/mL) in non-MTC thyroid cancer group. The gene discussed is CALCA; the disease is thyroid cancer.