There were numerous previous studies have identified or summarized the key biomarkers for HBV-related HCC, several of them were also have been identified as DEGs between tumor and adjacent normal tissues, such as AFP, glypican 3 (GPC3), midkine (MDK), karyopherin subunit alpha 2 (KPNA2), cyclin B1 (CCNB1) 67-71. This evidence concerns the gene MDK and hepatocellular carcinoma.