Anti-RSPO1 antibodies are used in the immunodetection of the protein R-spondin 1. In humans, the canonical protein has a reported length of 263 amino acid residues and a mass of 29 kDa. Its subcellular localization is in the nucleus and is secreted. Up to 3 different isoforms have been reported for this protein. It is found to be highly expressed in adrenal glands, ovary, testis, thyroid and trachea but not in bone marrow, spinal cord, stomach, leukocytes colon, small intestine, prostate, thymus and spleen. A member of the R-spondin protein family, RSPO1 is reported to be an activator of the canonical Wnt signaling pathway by acting as a ligand for LGR4-6 receptors. Post-translational modifications have been described, including glycosylation. Synonyms for this target antigen include R-spondin homolog and roof plate-specific spondin-1. RSPO1 gene orthologs have been reported in the mouse, rat, bovine, frog, zebrafish, chimpanzee and chicken species. A number of RSPO1 antibodies have been mentioned in research publications and have associated citations. Western Blot is a widely used application for these antibodies. ELISA and Immunohistochemistry are also common applications.