About the Authors
Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
Howard Hughes Medical Institute, Seattle, Washington, United States of America
Biodesign Institute, Arizona State University, Tempe, Arizona, United States of America
The authors have declared that no competing interests exist.
YD, SH, and SL conceived and designed the experiments. YD performed the experiments, except for AFM, which was performed by HW. YD and SH analyzed the data, except for AFM data analyzed by HW and SL. YD contributed reagents/materials/analysis tools. YD and SH wrote the paper.