Activator of G-protein Signaling 3 (AGS3) [or G-protein Signaling Modulator 1 (GPSM1)] mRNA and protein expression was aberrantly high in cystic collecting duct epithelial cells from multiple orthologous and non-orthologous rodent models of autosomal recessive (ARPKD) and ADPKD (Nadella et al., 2010; Kwon et al., 2012; Lenarczyk et al., 2015). Here, GPSM1 is linked to autosomal recessive polycystic kidney disease.