A xenoendocrinologist is a person, usually a medical doctor, who studies anatomy, physiology, diseases and disorders of the endocrine system in species other than his own. Dr. Jefferson Caldwell was a famous Federation xenoendocrinologist. His work in the field led him to be nominated three times for the Carrington Award, winning it finally (posthumously) in 2362. (Star Trek: The Cantabrian Expeditions: "Breaking Benjamin")