Barry J. Marshall, recipient of the 2005 Nobel Prize in physiology or medicine for his discovery of Helicobacter pylori as the cause of stomach ulcers, speaks May 30 at the “21st Century Science: Foundation for Innovation” symposium at the School of Medicine. Marshall spoke about his research to find the cause of ulcers and his experiences as an entrepreneur trying to reinvest intellectual property into budding biotechnology businesses. The symposium also featured panels with researchers, venture capitalists, life-science entrepreneurs, corporate executives and academic research officers.