Prokineticin-2 (PK2) is a cysteine-rich secreted protein that is expressed in the testis and, in lower levels, in the small intestine. PK2 regulates various biological functions, including gastrointestinal motility, angiogenesis and circadian rhythms. It is closely related to EG-VEGF (Prokineticin-1), and binds to two orphan B-protein-coupled receptors termed PK-R1 and PK-R2. Recombinant Murine Prokineticin-2 is an 11.6 kDa protein consisting of 103 amino acid residues, including ten cysteine residues that can potentially form five pairs of intra-molecular disulfide bonds.