This book is an edited version of the contributions to an international symposium commemorating the 20th anniversary of the Japanese Society of Lipid Peroxide and Free Radical Research held in Inuyama City, Japan. The papers are presented in mini-review style, so that the volume has assumed the form of an advanced guidebook for specialists. The pathophysiology of lipid peroxides and related free radicals is now recognized to be one of the most important issues in the pathogenesis of many diseases. This volume covers diverse topics such as retinal pathology, digestive diseases, antioxidant defence and cancer chemotherapy, as well as more abstract topics related to lipid peroxides and free radicals. The papers collected in this book will contribute much to the improvement of medical sciences, especially to that of clinical medicine, the main goal of which is human welfare.