Photobiology is the study of the interaction of light with living cells. It is applied in cancer research and treatment and is important to our growing understanding of the etiology and treatment of such skin and blood conditions as psoriasis and hyperbilirubinemia. Representing a broad range of disciplines, the contributors to this volume outline the prospects for x-ray lasers in biological research, present the sequences of photosynthetic reaction center protein genes and summarize the potential and complexities of laser treatment. This volume presents state-of-the-art research findings in this vital field.