Experimental AIH mice showed an increased hepatic Th22 cell frequency, increased serum IL-22 levels, and sustained replication of AhR.33 The levels of Th22 cells and IL-22 were found to decrease after the use of immunosuppressive drugs.33 However, Zenewicz et al180 found that IL-22 reduced the destruction of hepatocytes by the immune response during acute liver inflammation and that IL-22 deficiency sensitized hepatocytes in mice to liver inflammation. This evidence concerns the gene AHR and inflammation.