R-Spondin-2, also known as Rspo-2, is a growth factor belonging to the R-Spondin family. R-Spondins are four proteins that support adult stem cell proliferation, and act as Wnt modulators by signaling through the canonical Wnt/β-catenin pathway as agonists. LGR4, LGR5, and LGR6 have been identified as receptors for all four R-Spondins. R-Spondin-2 is expressed in endoderm-derived tissues and is an agonist of Wnt-3a signaling and an inhibitor of DKK-1, Activins, and BMP-4. It plays an important role in morphogenesis of respiratory tract and limbs, and induces cell proliferation of the gastrointestinal tissues.