Serum gastrin levels are generally elevated in patients with gastrin‐producing tumors (neuroendocrine tumors), severe gastric atrophy due to autoimmune gastritis (AIG) or H. pylori‐associated gastritis, and in those receiving potent acid suppressive therapy such as proton pump inhibitors [29, 30, 31]. The gene discussed is GAST; the disease is neuroendocrine neoplasm.