CALCA and medullary thyroid gland carcinoma: More recently, Censi and colleagues retrospectively evaluated 90 MTC patients during postoperative follow-up and found a strong relationship between calcitonin and ProCT, corroborating the relevant role of ProCT as an adjunctive biomarker to calcitonin, especially to exclude MTC structural recurrences in patients with a slight to moderate increase in calcitonin concentrations [46].