During the period of acute and chronic viral hepatitis, IL-35 immunosuppression functions mainly through promoting the proliferation and differentiation and CD8+ T cell function and inhibition of Th17 Treg cells T cell toxicity; CD8+ T cell-mediated cytotoxicity mechanisms include the direct cytolytic activity of target cells and noncytolytic activity of cytokine-mediated tissue damage [141–148]. This evidence concerns the gene CD8A and animal viral hepatitis.