The PROK2 gene provides instructions for making a protein called prokineticin 2. This protein interacts with another protein called prokineticin receptor 2 (produced from the PROKR2 gene). On the cell surface, prokineticin 2 attaches (binds) to the receptor like a key in a lock. When the two proteins are connected, they trigger a series of chemical signals within the cell that regulate various cell functions. Prokineticin 2 and its receptor are produced in many organs and tissues, including the small intestine, certain regions of the brain, and several hormone-producing (endocrine) tissues.