Results from the study indicated that the incidence that HCC patients have Syncytin-1 and HBsAg simultaneously expression or not was up to ~88.35% (91/103) (Fig. 2k, Table 1), higher than co-expression incidence that Syncytin-1 with any other clinicopathological parameters. The gene discussed is ERVW-1; the disease is hepatocellular carcinoma.