Orexins were first shown to be implicated in narcolepsy, insomnia [15,16,17,18,19,20,21] and stress responses [22,23,24,25], but it is worth mentioning that orexins have also been described to play major roles in other CNS disorders, comprising both neuropsychologic and neurodegenerative diseases. The gene discussed is HCRT; the disease is neurodegenerative disease.