University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania. Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania. Department of Food Science & Nutrition, University of Minnesota, St. Paul, Minnesota. Department of Medicine, Division of Gastroenterology, Hepatology, & Nutrition, University of Minnesota, Minneapolis, Minnesota. Department of Family Medicine and Community Health, University of Minnesota Medical School, Minneapolis, Minnesota. Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, New Jersey. Department of Pharmacology & Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania. Department of Preventive Medicine, University of Southern California Keck School of Medicine, Los Angeles, California. University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania. yuanj@upmc.edu.