8843n/aENSG00000255398n/aP49019n/aNM_006018n/aNP_006009n/aHydroxycarboxylic acid receptor 3 (HCA3), also known as niacin receptor 2 (NIACR2) and GPR109B, is a protein which in humans is encoded by the HCAR3 gene. HCA3, like the other hydroxycarboxylic acid receptors HCA1 and HCA2, is a Gi/o-coupled G protein-coupled receptor (GPCR). The primary endogenous agonist of HCA3 is 3-hydroxyoctanoic acid. HCA3 is also a low-affinity biomolecular target for niacin (aka nicotinic acid). Hydroxycarboxylic acid receptor 3 (HCA3), also known as niacin receptor 2 (NIACR2) and GPR109B, is a protein which in humans is encoded by the HCAR3 gene. HCA3, like the other hydroxycarboxylic acid receptors HCA1 and HCA2, is a Gi/o-coupled G protein-coupled receptor (GPCR). The primary endogenous agonist of HCA3 is 3-hydroxyoctanoic acid. HCA3 is also a low-affinity biomolecular target for niacin (aka nicotinic acid). HCA3 is a member of the hydroxycarboxylic acid receptor family of Gi/o-coupled GPCRs. The primary endogenous agonist of HCA3 is 3-hydroxyoctanoic acid. HCA3 is also a low affinity receptor for nicotinic acid (niacin)