Median CgA levels were significantly higher in patients with advanced GEP-NETs than in healthy individuals (93.8 ng/mL vs. 37.1 ng/mL; P<0.01), as well as significantly higher in patients with carcinoid syndrome or liver metastasis than in those without carcinoid syndrome (298.8 ng/mL vs. 82.9 ng/mL; P = 0.011) or liver metastasis (137.0 ng/mL vs. 64.4 ng/mL; P = 0.023). The gene discussed is CGA; the disease is carcinoid syndrome.