Peter Ratcliffe is a prominent British physician and researcher known for his work in the field of cellular responses to low oxygen levels, a process known as hypoxia. He has made significant contributions to understanding how cells adapt to reduced oxygen availability, which has implications for various medical conditions, including cancer and heart disease. In recognition of his groundbreaking research, Ratcliffe was awarded the Nobel Prize in Physiology or Medicine in 2019, sharing the honor with William Kaelin and Gregg Semenza. His discoveries have advanced the understanding of how oxygen levels regulate cellular metabolism and have opened new avenues for therapeutic interventions.