First, an increase in the level of IL-6 produced by various cells, including T-cells, B-cells, macrophages, endothelial cells, fibroblasts and so on, is observed in a variety of chronic inflammatory diseases (i.e. rheumatoid arthritis, Castleman's disease, systemic lupus erythematosus, systemic sclerosis); therefore, an elevated IL-6 level is not specific to patients with bowel ischemia [42]. This evidence concerns the gene IL6 and Castleman disease.