Involved in the avoidance response to the noxious chemicals and repellents such as quinine in ASH and ADL sensory neurons (PubMed:14988722). In response to the noxious chemical quinine, promotes dauer formation induced by pheromones such as the ascaroside ascr#3 in ASH nociceptive neurons (PubMed:26976437). Expressed in the nerve ring, neurons of the lateral and ventral ganglia, including the sensory neuron ADL, neurons in the retrovesicular ganglion and two neurons in the lumbar ganglion, PVQ and the sensory neuron PHB (PubMed:14988722). Expressed in ASH nociceptive chemosensory neurons (PubMed:14988722, PubMed:26976437). Not expressed in ASK sensory neurons (PubMed:14988722).