This volume of the subcellular Biochemistry series will attempt to bridge the gap between the subcellular events that are related to aging as they were described in the first volume of this set of two books and the reality of aging as this is seen in clinical practice. All chapters will start from the biochemistry or cell biology, where the data is available and work up towards the understanding that we have of aging in the various areas that are related to the subject. Key focus points for this volume are nutrition, external factors and genetics on aging. There will also be chapters that will focus on various organs or tissues in which aging has been well studied, like the eyes, the muscles, the immune system and the bones. The aim of the book project and the book project that is published in concert with this volume is to bring the subcellular and clinical areas into closer contact.