Nobel laureate Fred Ramsdell began his career at Darwin Molecular in Seattle, a biotech startup that was backed by Microsoft co-founders Bill Gates and Paul Allen. His work led to a Nobel Prize in Physiology or Medicine, shared with former colleagues Mary Brunkow and Shimon Sakaguchi of Osaka University in Japan for their pioneering work in regulatory T cells, or Tregs. The discovery of these cells changed therapeutics by showing that the immune system has a built-in braking mechanism that can be enhanced to treat autoimmune disease, transplant rejection and graft-versus-host disease. After leaving Darwin, he served as a scientific advisor for the Parker Institute for Cancer Immunotherapy, a nonprofit research institute that operates as a collaborative network across seven major U.S. cancer centers.