KLRK1 and hepatocellular carcinoma: Consistently, STAT3-blocked (or inhibited) hepatocellular carcinoma cells showed upregulated NKG2D ligands (i.e., MICA/B and ULBPs), and thereby cytotoxicity of NK cells treated with supernatant from STAT3-blocked hepatocytes was augmented with a concomitant elevation of molecules associated with NK cytolysis [54, 55].