TNF and anorexia nervosa: Studies examining tumor necrosis factor (TNF) levels have also resulted in decreased, unchanged, or increased levels of this cytokine [55,69,76,100,101,102,103,104,108,109], but a majority of the studies suggest increased secretion of TNF by immune cells in anorexia nervosa [55,69,76,100,101,103,104,109].