Early on, Dr. Sullivan and the team at Fred Hutchinson Cancer Research Center developed a systematic investigative approach for the diagnosis and treatment of chronic graft-versus-host disease (GVHD), the major cause of late morbidity and non-relapse mortality following allogeneic stem cell transplantation (SCT). As a result of this work, it became clear that blood and marrow transplant recipients require systematic long-term follow-up to evaluate and treat late complications of high-dose chemoradiotherapy and SCT.