The severity of malnutrition in IBD patients is dependent on the activity, duration, and extent of the disease and, in particular, on the magnitude of the inflammatory systemic response mediated by pro-inflammatory cytokines such as tumor necrosis factor (TNF)-α and interleukins-1 and -6, which can increase catabolism and lead to anorexia [26]. The gene discussed is TNF; the disease is inflammatory bowel disease.