In particular, some studies show that treatment with orexin A reduces the secretions of IL-1β, IL-6 and IL-8, as well as the production of reactive oxygen species (ROS) [35], which is why hypocretins may play a direct role in neurodegenerative diseases including PD and AD, although these mechanisms are less well known [36]. The gene discussed is HCRT; the disease is Parkinson disease.