The tenth edition of Greenspan’s Basic & Clinical Endocrinology is dedicated to the memories of four outstanding endocrinologists—Dr. John Baxter, Dr. Claude Arnaud, Dr. Melvin Grumbach, and, most especially, Dr. Francis Greenspan who was responsible for taking the initial steps to assemble this textbook more than thirty years ago. Each of these individuals was an outstanding endocrine scientist and/or clinical endocrinologist in the global endocrine community, and each contributed enormously to the success of this textbook.