Acknowledgements
We thank Ms Yukiko Koyama (Central Research Laboratory, Shiga University of Medical Science) for her technical assistance (sequencing).
We also thank NAI Inc. (Yokohama, Japan) for reviewing the English.
Declaration of interest
The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.
Funding
This work was supported in part by Grants-in-Aid for Scientific Research from the Japan Society for the Promotion of Science (25462712 to SM and 25462711 to HU).
Supplemental data for this article can be accessed on the publisher’s website at http://dx.doi.org/10.3109/13816810.2015.1120319.