About the Authors

Janet K Shim

To whom correspondence should be addressed. E-mail: Janet.Shim@ucsf.edu

Ann J Russ
Sharon R Kaufman

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

The data reported here are part of a larger collaboration among all three authors, all of whom have contributed substantially to the design of this larger project, and to its data collection, analysis, and interpretation. The first author, Janet K. Shim, collected the data discussed in this Essay and took the lead in writing the preliminary draft. All three authors contributed to subsequent critical revisions for intellectual content, and have approved the final version of this manuscript.