ORs Rule the Roost in the Olfactory System

Abstract
It is well established that each olfactory neuron of the mammalian olfactory system expresses only one olfactory receptor (OR) out of the 1000 OR proteins encoded by the mammalian genome. In their Perspective, Lewcock and Reed discuss new findings ( Serizawa et al.) that show how the OR protein itself participates in a negative feedback mechanism, which ensures that only one OR is expressed in each olfactory neuron.