Specific melatonin agonists are becoming available, which lack binding to the MT3/quinone reductase receptor; these agents will help to isolate the specific effects mediated by the high-affinity melatonin receptors, and may become important options for pharmacologic treatment of insomnia without the potential for side effects from interactions with the MT3/quinone reductase binding site [23]. This evidence concerns the gene MT3 and insomnia.