Treatment with the chemotherapeutic agent cisplatin suppresses AR expression by two distinct mechanisms: by increasing miR-34a-5p to suppress AR expression and by altering AR ubiquitination to accelerate AR protein degradation; suppressed AR expression may result in up-regulation of ULBP2, a natural-killer group 2 member D (NKG2D) ligand, to enhance the cytotoxicity of NK cells against HCC 30. This evidence concerns the gene KLRK1 and hepatocellular carcinoma.