Anti-RGS21 antibodies are used in the immunodetection of the protein regulator of G protein signaling 21. In humans, the canonical protein has a reported length of 152 amino acid residues and a mass of 17.7 kDa. It is ubiquitously expressed across many tissue types. RGS21 is known to inhibit signal transduction by increasing the GTPase activity of G protein alpha subunits thereby driving them into their inactive GDP-bound form. Synonyms for this target antigen include regulator of G-protein signalling 21. RGS21 gene orthologs have been reported in the mouse, rat, bovine, chimpanzee and chicken species. ELISA, Western Blot, Immunocytochemistry, Immunofluorescence, and Immunohistochemistry are common applications for RGS21 antibodies.