Saar Gill, MD, PhD, brings a unique perspective to this update on blood and marrow transplantation from the annual Updates in Oncology meeting at Penn Medicine. In this far-ranging discussion, Dr. Gill examines the questions at the core of each of four key areas in the field-donor selection, conditioning, graft source and GVHD prophylaxis and management-to arrive at conclusions that summarize the current knowledge of blood and marrow transplantation.