Wong DKH, et al. - Via clinical information and liver tissues from 110 hepatitis B surface antigen (HBsAg)-negative patients who had liver resection or liver biopsy between November 2002 and July 2017 in Hong Kong, researchers studied the incidence of occult hepatitis B virus (HBV) infection (OBI) in patients with hepatocellular carcinoma (HCC) and other liver diseases. In addition, they examined whether HBV DNA has integrated into the DNA of hepatocytes in patients with OBI and HCC. In a clinical data and liver tissue analysis of 90 HBsAg-negative HCC patients, the authors found that nearly 70% had OBI, 70% of whom had integrated HBV DNA into the liver cell DNA. Of these patients, 90% had no cirrhosis. Integrated HBV DNA near hepatic oncogenes, and these integrations could promote liver cancer development.