A comprehensive cytokine detection revealed that PD1Hi CD8+ T cells not only down-regulate canonical CD8+ T cell effector cytokines IFN-γ, IL-2 TNF-α, cytotoxic degranulation marker CD107a and the capacity to kill HCC tumor cell HCCLM3, but also the expression of IL-4, IL-17A and IL-22, suggesting a general defect in cytokine production and anti-tumor ability. Here, IL17A is linked to hepatocellular carcinoma.