Trace amine-associated receptor 4 (Taar4)

Olfactory receptor specific for 2-phenylethylamine, a trace amine present at high concentration in the urine of carnivore species, plays a key role in fear and avoidance reactions. 2-phenylethylamine functions as a kairomone from the chemical detection of carnivore odor and triggers fear in mice.

This receptor is probably mediated by the G(s)-course of G-proteins which activate adenylate cyclase. .