Nomenclature	GPR19	GPR20	GPR21	GPR22	GPR25	GPR26	GPR27
HGNC, UniProt	GPR19, Q15760	GPR20, Q99678	GPR21, Q99679	GPR22, Q99680	GPR25, O00155	GPR26, Q8NDV2	GPR27, Q9NS67
Comments	–	Reported to inhibit adenylyl cyclase constitutively through Gi/o [743]. GPR20 deficient mice exhibit hyperactivity characterised by increased total distance travelled in an open field test [213].	Gpr21 knockout mice were resistant to diet‐induced obesity, exhibiting an increase in glucose tolerance and insulin sensitivity, as well as a modest lean phenotype [1516].	Gene disruption results in increased severity of functional decompensation following aortic banding [10]. Identified as a susceptibility locus for osteoarthritis [520, 975, 2011].	–	Has been reported to activate adenylyl cyclase constitutively through Gs [923]. Gpr26 knockout mice show increased levels of anxiety and depression‐like behaviours [2209].	Knockdown of Gpr27 reduces endogenous mouse insulin promotor activity and glucose‐stimulated insulin secretion [1059].