KLRK1 and viral infectious disease: Various risk factors lead to the occurrence of HCC, such as hepatitis B virus (HBV) infection, hepatitis C virus (HCV) infection, alcohol (ethanol), non‐alcoholic fatty liver disease (NAFLD), carcinogen/toxin exposure, genetic factors, etc.19The expression of the NKG2D ligands might serve as indicators of cellular stress, which could be induced by the viral infection or malignant transformation.20