About the Authors

Zhongming Ma

Affiliation Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America

Jun Kong

Affiliation Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America

Roland G. Kallen

rgk@mail.med.upenn.edu

Affiliations Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America, Mahoney Institute for Neuroscience, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: RGK. Performed the experiments: ZM JK. Analyzed the data: ZM. Wrote the paper: RGK.