INS and Insulin resistance: IL-22 plays an important role in lipid metabolism, as it improves insulin sensitivity, protects the intestinal mucosal barrier, reduces endotoxemia and chronic inflammation, IL-22 receptor-deficient and high-fat-fed mice are prone to metabolic disorders, while administration of exogenous IL-22 to obese mice reversed the induced symptoms like hyperglycemia and insulin resistance (Wang et al., 2014).