The cholecystokinin B receptor also known as CCKBR or CCK₂ is a protein that in humans is encoded by the CCKBR gene.

This gene encodes a G-protein coupled receptor for gastrin and cholecystokinin (CCK), regulatory peptides of the brain and gastrointestinal tract. This protein is a type B gastrin receptor, which has a high affinity for both sulfated and nonsulfated CCK analogs and is found principally in the central nervous system and the gastrointestinal tract. A misspliced transcript variant including an intron has been observed in cells from colorectal and pancreatic tumors. [provided by RefSeq, Jul 2008]. Publication Note: This RefSeq record includes a subset of the publications that are available for this gene. Please see the Gene record to access additional publications.
Function: Receptor for gastrin and cholecystokinin. The CKK-B receptors occur throughout the central nervous systemwhere they modulate anxiety, analgesia, arousal, and neuroleptic activity. This receptor mediates its action by association with G proteins that activate a phosphatidylinositol-calcium second messenger system

Function: Isoform 2 is constitutively activated and may regulate cancer cell proliferation via a gastrin-independent mechanism.