Production and release of pro-inflammatory cytokines including tumor necrosis factor (TNF)-α, interleukin (IL)-1β and interleukin (IL)-6 (52), secreted by a variety of immune cells including neutrophils, macrophages, T- and B- cells, dendritic cells, and vascular endothelial cells (53) also follow tissue injury, and together with the appearance of neutrophils in both ARDS and IBD, are central to the initiation and maintenance of inflammation (53). Here, TNF is linked to acute respiratory distress syndrome.