About the Authors
Fox Chase Cancer Center, Philadelphia, Pennsylvania, United States of America
The authors have declared that no competing interests exist.
Conceived and designed the experiments: EKB AVT. Performed the experiments: EKB EK MG MJ AVT. Analyzed the data: EKB EK MJ AVT. Contributed reagents/materials/analysis tools: EKB AVT. Wrote the paper: EKB AVT.