Conclusion
In summary, we found increased IL-35 expression in HCC serum and tumor tissues. Elevated IL-35 has a critical role in the immunosuppressive tumor environment by affecting the balance between Tregs and cytotoxic T cells. Further studies are required to determine the regulatory network of IL-35 to effector T cells and how to modulate it. Dissection of the precise mechanism and corresponding management will hopefully lead to the development of more effective treatment methods for HCC patients.