Nomenclature	GPR109A	GPR109B	GPR81
Other names	Niacin receptor 1, HM74A, Nic1, Puma-G,	Low-affinity nicotinic acid receptor, HM74, Nic2	GPR104
Ensembl ID	ENSG00000182782	ENSG00000182442	ENSG00000196917
Principal transduction	Gi/o (Soga et al., 2003); Tunaru et al., 2003; Wise et al., 2003)	Gi/o (Soga et al., 2003; Wise et al., 2003)	Gi/o (Ge et al., 2008)
Selective agonists	Nicotinic acid (Soga et al., 2003; Tunaru et al., 2003; Wise et al., 2003), acipimox (Wise et al., 2003), 3-hydroxybutyrate (Taggart et al., 2005)	3-Hydroxyoctanoic acid (Ahmed et al., 2009), IBC293 (Semple et al., 2006)	Lactate (Cai et al., 2008; Liu et al., 2009)
Probes	[3H]-Nicotinic acid (Soga et al., 2003)	–	–