GRN and hepatocellular carcinoma: In hepatocellular carcinoma, progranulin rendered tumor cells resistant to natural killer (NK) cytotoxicity by promoting the downregulation of MHC class I chain-related molecule A (MICA) and upregulation of human leukocyte antigen E (HLA-E), the ligands of NK activator receptor NK group 2 member D (NKG2D) and NK inhibitory receptor CD94/NKG2A, respectively [97].