Cholecystokinin is a brain/gut peptide. In the gut, it induces the release of pancreatic enzymes and the contraction of the gallbladder. In the brain, its physiologic role is unclear. The cholecystokinin pro-hormone is processed by endo- and exo-proteolytic cleavages. Two transcript variants encoding the same protein have been found for this gene. [provided by RefSeq, Mar 2010].