As always, Harper’s Illustrated Biochemistry continues to emphasize the close relationship of biochemistry to the understanding of diseases, their pathology, and the practice of medicine. With the retirement of long-time contributor David A. Bender, Prof. Owen P. McGuinness of Vanderbilt University has joined as a new coauthor. In addition to the fresh perspectives and novel insights provided by Prof. McGuinness, the contents of most chapters have been updated and provide the reader with the most current and pertinent information. For example, in Chapter 6 the description of the Bohr effect’s contributions to CO₂ transport and release from the lungs has been reorganized and expanded, while Chapter 9 has been updated and reorganized to include expanded coverage of zymogen activation in enzyme regulation.