The present study shows that the cytokine IL-15 and a humanized antibody specific for a ligand recognized by a major activating receptor (NKG2D) expressed by a subset of lymphocytes named natural killer (NK) cells can restore dysfunctional NK cell responses in patients affected by the most common liver cancer hepatocellular carcinoma. This evidence concerns the gene KLRK1 and hepatocellular carcinoma.