R-spondin 3 homolog (Xenopus laevis), or R-spondin 3, is a human gene encoded by RSPO3. It may also be known as: R-spondin-3; hPWTSR; Roof plate-specific spondin-3; hRspo3; Thrombospondin type-1 domain-containing protein 2; Protein with TSP type-1 repeat; CRISTIN1; PWTSR; THSD2. The encoded protein has an amino acid length of 272 and a mass of 30.9 kDa. Other isoforms may exist. R-spondin 3 homolog (Xenopus laevis) is a member of the R-spondin family. Homologs of this gene exist in other organisms, including: Mouse, Rat, Zebrafish, Frog, Chicken.