According to the World Health Organization, about 2 billion persons worldwide have been infected with Hepatitis B virus (HBV). More than 350 million are chronically infected worldwide with a high risk of developing liver cirrhosis and hepatocellular carcinoma (representing 1 million deaths per year).

Based on sequence divergence in the entire genome of >8%, HBV genomes have been classified into eight groups designated from A to H. The genotypes of HBV have distinct geographical distributions. Although preliminary clinical studies seem to indicate that there is an association between HBV genotype and natural history of infection and response to antiviral therapy, further evaluations on larger collectives of patients are necessary to give a clearer picture of the subject.

We invite investigators to contribute original research articles as well as review articles that will stimulate the continuing efforts to understand the molecular pathology and clinical impact of HBV genetic variability. We are particularly interested in papers that explore this genetic variability in humans and animals and articles describing new options for diagnosis via immunoassays or molecular assays as well as any data that may help to understand the clinical impact of HBV variability. Potential topics include, but are not limited to:

• Recent technical development of sensitive assays to detect HBV
• Description of new HBV mutants and/or sub-genotypes
• Role of genetic variability in relation to clinical picture, the response to treatment, and the long-term prognosis

Before submission authors should carefully read over the journal's Author Guidelines, which are located at http://www.hindawi.com/journals/heprt/guidelines.html. Prospective authors should submit an electronic copy of their complete manuscript through the journal Manuscript Tracking System at http://mts.hindawi.com/ according to the following timetable: