RSPO1 activates the canonical Wnt signaling pathway by binding to the LGR4-6 receptor, triggering an increase in target gene expression. It inhibits ZNRF3, regulates the Wnt signaling pathway, and negatively regulates the TGF-β pathway. RSPO1/R-spondin-1 Protein, Mouse (189a.a, His) is the recombinant mouse-derived RSPO1/R-spondin-1 protein, expressed by E. coli , with N-6*His labeled tag.