SSTR2A (somatostatin receptor 2A) is one of the two isoforms of the somatostatin receptor 2, a G-protein coupled receptor for somatostatin-14 and somatostatin-28. Binding to the receptor inhibits adenylyl cyclase and calcium channels, resulting in several organ-specific functions, including inhibition of secretion of glucagon and insulin in the pancreas, inhibiting secretion of gastric acid, pepsin, and bile in the GI tract, and inhibiting secretion of neurotransmitters in the brain. The receptor thereby affects the body’s locomotor, sensory, autonomic and cognitive functions. Also, somatostatin can cause cell cycle arrest, as well as induce agonist-dependent endocytosis. The receptor also binds synthetic somatostatin (octreotide), which can be used to image or target somatostatin-secreting neuroendocrine tumors. It is mostly expressed in the cell membrane of pancreatic alpha and beta cells, various regions of the brain, the adrenal medulla and neuroendocrine cells. References: Oncol Lett 2017 13(3):1165; Cell Phys Biochem 2002 12(1):31; Am J Phys Endoc Metab 2012 303(9):E1107; Bioch Biphys Acta 2001 1616(1):1