He is considered the world's pre-eminent scientist studying the vascular pathobiology of sickle cell disease. His contributions caused a fundamental paradigm shift in the understanding and in the strategies developed for treatment of the disease. In 1998, Hematologists from around the world were polled to identify the most important scientific developments over the previous 25 years of sickle disease research, and Dr. Hebbel's 1980 observation of abnormally adhesive sickle red cells topped the list. He has had a key role in the establishment of the University of Minnesota's international reputation in the areas of minority health research, Hematology and vascular biology. He has made seminal contributions to these areas of research including the development of a gene-based therapy to treat hemophilia. He has authored over 150 publications including peer-reviewed journals, a book, book chapters and reviews. Fifteen of his publications have been printed in the New England Journal of Medicine and the Journal of Clinical Investigation. He has been elected to membership in the American Society for Clinical Investigation and the Association of American Physicians. His research has been continuously supported since 1979 from highly competitive funding sources including the National Institute of Health, and he received large laboratory grant funding from the National Hemophilia Foundation, which grants only one of these awards worldwide each year. Dr. Hebbel has a strong commitment to graduate education, mentorship and minority science development. He has founded and served as director of several programs, which provide mentorship, career stimulation, and critical thinking skills including the Internal Medicine Residency's Academic Pathway program. He has also made exceptional service contributions both within the college and the University as well as to the profession.