Thomas Witzig

Dr. Thomas Witzig earned a B.S. in Biology from Illinois State University and an M.D. from the University of Illinois College of Medicine. He completed an internal medicine residency at the University of Iowa, followed by a hematology/oncology fellowship at Mayo Clinic, where he also conducted laboratory research in multiple myeloma and lymphoma under Drs. Philip Greipp and Robert A. Kyle. He joined the Mayo Clinic staff in 1986.

Dr. Witzig’s clinical and research interests focus on blood cancers and the biological mechanisms underlying COVID-19. His current work investigates therapies targeting DNA damage repair and signal transduction pathways in lymphoma. He has played a leading role in the development of radioimmunotherapy, mTOR inhibitors, and immunomodulatory agents such as lenalidomide. His research group was the first to demonstrate the effectiveness of rituximab for IgG4-related autoimmune diseases affecting organs including the orbit and pancreas. During the COVID-19 pandemic, his laboratory identified a mechanism contributing to severe infection that is now being investigated in patients with Long COVID. His research has been supported by the National Cancer Institute, the Predolin Foundation, and other organizations.

Dr. Witzig has received numerous honors, including the Department of Medicine Outstanding Investigator Award, the Henry S. Plummer Distinguished Physician Award, and the Barbara Woodward Lips Professorship.

An accomplished educator and mentor, Dr. Witzig has delivered invited lectures at regional, national, and international meetings. He has authored or co-authored more than 500 publications—including peer-reviewed articles, books, book chapters, and letters—and more than 600 scientific abstracts.