Dr. Leigh Ann Burns Naas is Vice President of Nonclinical Safety and Pathobiology at Gilead Sciences. Throughout her career, her work has focused on strategic aspects and the design of safety programs to support chemical product development and registration, and the clinical development and licensure for small molecules and biotherapeutics, including vaccines. She began her career in toxicology at Dow Corning Corporation where she served as Immunotoxicology Lab Supervisor and subsequently became Group Leader for Americas Product Toxicology within Health, Environmental and Regulatory Affairs. She joined Pfizer, Inc. at their La Jolla Laboratories site and over her tenure there served as a Drug Safety Research and Development Global Therapeutic Area Leader for Infectious Disease and Oncology. Leigh Ann has demonstrated a long commitment to promoting advancements in basic and applied toxicology and the impact of toxicological sciences on human and environmental health across multiple scientific organizations and in the literature, and in the training/education of the next generation of toxicologists. She is a member of the Editorial Board for the International Journal of Toxicology and Journal of Immunotoxicology. In addition to being a Fellow of the ATS, she is a Diplomate of the American Board of Toxicology (ABT) and a European Registered Toxicologist (UK). A former member of the Board of Directors of the ABT, Leigh Ann has also been very active in both the Society of Toxicology (SOT) and the American College of Toxicology (ACT). She is a Past President of the ACT and is currently the Vice President of the SOT. Leigh Ann received her doctorate degree in pharmacology and toxicology from the Medical College of Virginia/VCU with an emphasis in immunotoxicology, and completed a postdoctoral fellowship in biochemical and molecular immunology at the Mayo Clinic in Rochester, MN.