This book introduces the function and effects of the functional food, AHCC (Active Hexose Correlated Compound), which is extracted from a culture of shiitake mushroom mycelia. Fifteen years have passed since The Basic and Clinical Researches on AHCC, which I co-edited with fellow ICNIM chairpersons. In that period, research on AHCC has spread throughout the world, and a great deal of new knowledge has been accumulated. The Clinician's Guide to AHCC has been compiled to present this accumulated knowledge with contributions from the researchers who engaged in the studies. The effects of AHCC on cancer prevention and cancer treatment have been mainly researched up until now; however, AHCC exerts more functions than just an anti-carcinogenic effect, such as anti-infective benefits against fungi, viruses, and parasites with its immunomodulating effects, anti-stress effect, chemotherapy-enhancing effect, and mitigating effect for immunosuppression. I hope that this book will be helpful to deeply understand AHCC not only for clinicians and healthcare professionals, but also for consumers who will use AHCC in various clinical situations. ¿Prof. Masuo Hosokawa (Extracted from Preface) About the Publisher International Congress on Nutrition and Integrative Medicine (ICNIM) is dedicated to the field of nutrition, complementary and integrative medicine or, more broadly, integrative health, which is an important approach for disease prevention and global health promotion. ICNIM promotes experimental and clinical research in the field, publishes scientific evidence and relevant topics, and organizes annual and associated meetings to provide knowledge and updated information for investigators and clinicians in related fields.