However, elevated calcitonin levels can be observed in conditions other than MTC, such as acute trauma, chronic pulmonary diseases, chronic renal failure, hypercalcemia, hypergastrinemia, inhalation injury, other neuroendocrine tumors, pseudohypoparathyroidism, and thyroiditis [16,17,18,19]. This evidence concerns the gene CALCA and neuroendocrine neoplasm.