Regulator of G-protein signaling (RGS) proteins contain an 120 amino acid conserved domain, termed the RGS domain, that acts as a GTPase-activating protein that acts to reduce the signal transmitted by the receptor-activated G-alpha subunit (1,2). RGS22 is a recently identified member of this family that localizes to the testis and can interact with guanine nucleotide binding proteins alpha 11, 12, and 13 (GNA11, GNA12, and GNA13). While RGS22 has been postulated to play a role in spermiogenesis in the testis, it is also expressed in several cancer cell lines with an epithelial origin and associated with cancer metastasis. Its overexpression in a highly metastatic cancer causes a decrease in cell migration and a reduction of the invasive potential of the cells, suggesting that RGS22 may be a potential prognostic biomarker for metastasis.Synonyms: Regulator of G-protein signaling 22