Background：

This gene encodes a secreted activator protein with two cysteine-rich， furin-like domains and one thrombospondin type 1 domain. The encoded protein is a ligand for leucine-rich repeat-containing G-protein coupled receptors (LGR proteins) and positively regulates the Wnt signaling pathway. In mice， the protein induces the rapid onset of crypt cell proliferation and increases intestinal epithelial healing， providing a protective effect against chemotherapy-induced adverse effects. Alternative splicing results in multiple transcript variants.