For detection of OBI -HBV DNA nucleic acid testing should be implemented even if anti-HBc and anti-HBs were negative especially in endemic area and in suspected high-risk cases (populations at high risk of parenterally transmitted infections) with probable previous exposure before blood and organ donation, transplantation, and chemotherapy and in hemodialysis and cryptogenic chronic hepatitis. The gene discussed is KRT88P; the disease is chronic hepatitis.