And, GEP renders hepatocellular carcinoma cells resistant to NK cytotoxicity by down-regulating surface expression of MHC class I chain-related molecule A (MICA), ligand for NK activated receptor NK group 2 member D (NKG2D), and up-regulating human leukocyte antigen-E (HLA-E), ligand for NK inhibitory receptor CD94/NKG2A 102. The gene discussed is KLRK1; the disease is hepatocellular carcinoma.