Deep sleep is of particular interest in IBD because of its well-established role in immunological processes: pro-inflammatory cytokines such as IL-1, IL-6, and TNF-α are implicated in poor sleep and specifically disrupt deep sleep, and are also involved in the pathogenesis of IBD.40,41 Therefore, optimizing deep sleep could positively affect the disease course of IBD.42 Besides, there is some evidence that long-term meditation practice is associated with improved deep sleep.43 The gene discussed is TNF; the disease is inflammatory bowel disease.