GRN and hepatocellular carcinoma: The correlation between the serum granulin–epithelin precursor (GEP) and NK cell activity in patients with HCC in the data of Cheung et al. [86] had been demonstrated that the level of GEP in HCC tissues was significantly higher than that in non-tumor liver tissues, and was not related to the number of NK cells in the peripheral blood of patients with HCC.