The First Miyakawa Memorial Research Foundation (MMRF) Meeting on Viral Hepatitis held in Tokyo in January 2003 focussed on the clinical relevance of HBV genotypes in the manifestation of chronic liver disease as well as the development of new antiviral treatment of chronic hepatitis B. Since the late 1990s, chronic hepatitis B has been treated worldwide with the nucleotide analogue lamivudine. During the meeting lamivudine therapy was discussed in depth with attention being focussed not only on the latest breakthroughs but also on the indications for and the duration of the therapy. In addition, coping strategies for dealing with lamivudine-resistant mutants were also explored. This volume provides the latest findings on how HBV genotypes influence the clinical manifestation and the response to lamivudine therapy.