HLA-E and hepatocellular carcinoma: Granulin-epithelin precursor (GEP), a hepatic oncofetal protein, was found to up-regulate NKG2A and HLA-E in the HCC microenvironment to enhance HCC cell invasion and resistance to human NK cell cytotoxicity, while downregulated MICA (MHC class I chain-related molecule A), the ligand for the stimulatory receptor NKG2D [186], a blockade of GEP by monoclonal antibody was demonstrated able to sensitized HCC cells to NK cytotoxicity.