HBV is a partially double-stranded relaxed circular DNA (rcDNA) virus, which enters the hepatocytes through a liver-specific receptor, sodium taurocholate cotransporting polypeptide (NTCP)3, and chronic HBV infection could lead to liver hepatitis, cirrhosis, eventually, hepatocellular carcinoma (HCC). The gene discussed is SLC10A1; the disease is hepatocellular carcinoma.