Duodenal Gastrinoma, also known as duodenal gastrin-producing neuroendocrine tumor, is related to diarrhea and duodenal ulcer. An important gene associated with Duodenal Gastrinoma is MEN1 (Menin 1), and among its related pathways/superpathways are GPCR downstream signalling and Class A/1 (Rhodopsin-like receptors). Affiliated tissues include pancreas and lymph node, and related phenotypes are homeostasis/metabolism and endocrine/exocrine gland