About the Authors
Developmental Biology Program, Sloan-Kettering Institute, New York, New York, United States of America
Biochemistry, Cell, and Molecular Biology Program, Weill Graduate School of Medical Sciences of Cornell University, New York, New York, United States of America
The authors have declared that no competing interests exist.
The author(s) have made the following declarations about their contributions: Conceived and designed the experiments: MV AKH. Performed the experiments: MV LN AKH. Analyzed the data: MV AKH. Contributed reagents/materials/analysis tools: MV LN SS AKH. Wrote the paper: MV AKH.