About the Authors
Department of Microbiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
Tumor Virus Molecular Biology Section, Laboratory of Cellular Oncology, National Cancer Institute, Bethesda, Maryland, United States of America
The authors have declared that no competing interests exist.
Conceived and designed the experiments: XW JL RMS CBB JY. Performed the experiments: XW JL RMS JJ. Analyzed the data: XW JL RMS JJ. Contributed reagents/materials/analysis tools: RMS CBB. Wrote the paper: XW RMS CBB JY.