The mean serum CgA levels in the subjects with carcinoid tumors, insulinomas, gastrinomas, and non-functioning Pan-NETs were 688 ng/ml, 105 ng/ml, 772 ng/ml and 306 ng/ml, respectively, as compared to the control levels of about 100 ng/ml [45]. The gene discussed is CGA; the disease is gastrin-producing neuroendocrine tumor.