HCRT and COVID-19: Orexin A influences not only energy homeostasis, sleep–awake behaviour, nociception reward seeking, and food and drug addiction, but also reproduction, cardiovascular, and adrenal function.13, 14, 15 In addition, recent research suggests that orexin A may also play a significant role in the modulation of the immune response and inflammatory processes, which are critically implicated in the pathogenesis of severe COVID-19.16, 17, 18, 19