Peter Klein is a Professor of Medicine and Attending Physician in the Division of Hematology-Oncology at the Perelman School of Medicine at the University of Pennsylvania. He obtained his MD and PhD at Johns Hopkins, completed residency at the Massachusetts General Hospital, postdoctoral fellowship at Harvard University, and then joined the faculty of the University of Pennsylvania School of Medicine and was appointed as an Investigator with the Howard Hughes Medicine Institute. Dr. Klein’s research focuses on developmental biology and the signals that control hematopoietic stem cells (HSCs), which are responsible for the production of all blood cells. His group discovered a method to culture and expand normal HSCs in the laboratory to improve HSC transplantation. His group also explores how disruption of HSC signaling leads to hematopoietic malignancies such as myelodysplasia and leukemia and is exploring novel approaches to target these pathways for the treatment of blood cancers.