Interactome analysis with current standard HCC biomarker AFP, its interacting partners (TP53, FOXA1, FOXA3, GPC3, IGFBP1, NR3C1, F2, AHSG, ACTL6A and JUN) along with DKK1 and MDK filtered 11 candidates ADH6, APOA5, APOC3, C8A, CYP2A6, F10, GSTM1, HSD11B1, MBL2, SERPINC1 and UPB1 as potential circulating biomarkers (Fig 4). The gene discussed is CYP2A6; the disease is hepatocellular carcinoma.