Hydroxycarboxylic acid receptor

The hydroxycarboxylic acid receptor (abbreviated HCA receptor and HCAR) family includes the following human proteins:^[1]

• Hydroxycarboxylic acid receptor 1 (HCA₁, formerly known as GPR81)
• Hydroxycarboxylic acid receptor 2 (HCA₂, formerly known as niacin receptor 1 and GPR109A)
• Hydroxycarboxylic acid receptor 3 (HCA₃, formerly known as niacin receptor 2 and GPR109B)