IL6 and inflammatory bowel disease: In IBD, as in chronic inflammatory conditions, a significant reduction in plasma and muscle IGF1 can be seen in response to the elevated concentrations of TNF-alpha and IL-6, cytokines that cause GH resistance in liver and muscles, inducing downregulation of mTOR pathway with activation of ubiquitin ligands and expression of enzymes involved in protein degradation, in particular atrogin-1, MuRF1, and MUSA1 [39–41].