Trace amine receptors (TAARs) are a family of G protein-coupled receptors that are activated by trace amines, which are a group of endogenous amines that include tyramine, β-phenylethylamine, and tryptamine. To date, 9 TAARs have been identified in humans: TAAR1, TAAR2, TAAR5, TAAR6, TAAR8, TAAR9, TAAR4, TAAR7, and TAAR3. These receptors are widely expressed in various tissues and organs and play a role in regulating various biological processes such as neurotransmission, immune response, and olfaction.