Karla Kirkegaard, Ph.D., is the Violetta L. Horton Research Professor of Genetics and former Chair of the Department of Microbiology and Immunology in the Stanford University School of Medicine. She received her Ph.D. in Biochemistry and Molecular Biology with James C. Wang at Harvard University, and performed her postdoctoral work in the laboratory of David Baltimore at the Whitehead Institute. As an Assistant and Associate Professor at the University of Colorado in Boulder, she received numerous awards, including a fellowship from the David and Lucile Packard Foundation, an American Cancer Society Young Investigator Award, a Searle Scholar Award, and sponsorship by the Howard Hughes Medical Institute. Dr. Kirkegaard combined her interests in biochemistry, cell biology, and genetics in the study of RNA virology, using poliovirus and other positive-strand RNA viruses to understand the cell biology of viral infections and the genetics of viral variability. Since her move to Stanford University School of Medicine in 1996, her interests have focused increasingly on the impact of basic science discoveries on the transmission of viruses in infected hosts. Kirkegaard’s honors include an Ellison Foundation Senior Scholar Award in Global Infectious Disease and, in 2006, the NIH Director’s Pioneer Award, for her approach to guide the selection of antiviral targets with the goal of suppressing the drug-resistant RNA genomes that will inevitably be formed due to the high error rates of RNA replication. She has been recently elected as a Member of the National Academies of Arts and Sciences and a Fellow of the American Association for the Advancement of Science. Her work continues to focus on the mechanisms of diversity and propagation of viruses and suppression of this diversity and spread.