The scope of this book is very broad, covering a wide range of areas in HBV/HDV and HCV research, including both basic and clinical science. The selected topics range from epidemiology, immunology, molecular virology and oncology, to clinical therapy. "Chronic Hepatitis B and C" consists of 13 chapters, each being a review of a special topic on HBV or HCV. While review articles on a special topic can be found in periodical journals, they tend to be more restricted in presentation. Therefore, this book will provide more in-depth coverage of what are presented as 'unpublished results' and 'data not shown' in journal articles. Furthermore, several authors in this book do not write review articles regularly. Some authors wrote reviews on a specific topic regularly, but they tried a new topic in this book (e.g., 'Dr. YF Liaw on natural course', 'Dr. Shih on virion release', 'Dr. Michael Lai on lymphotropism of HCV', etc.). Overall, the book will offer useful information at the cutting age.