Suggested mechanisms for a contribution of Tc17 cells to an immunosuppressive tumor microenvironment include the recruitment of regulatory T cells (TREG) via the CCR6-CCL20 axis indicated by increased levels of CCL20 in HCC samples, especially in those infiltrated with IFN-γ-negative Tc17 cells [195]. This evidence concerns the gene CCR6 and hepatocellular carcinoma.