AFP and hepatocellular carcinoma: α-Fetoprotein (AFP) overexpressed by HCC cells was demonstrated to indirectly impair interlukine-12 (IL-12) production from dendritic cells (DCs), which results in attenuated cytotoxic effector molecules release, decreased expression of natural killer group 2, member D (NKG2D), an activating receptor on NK cells, and subsequently inhibiting activation and ability of NK cells [80, 81].