Nature Communications 6: Article number: 6063 (2015); Published 28 January 2015; Updated 30 March 2015.

The financial support for this Article was not fully acknowledged. The Acknowledgements should have included the following:

This study was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (2014055007), Ministry of Education, Science and Technology (2012004585), and by the Korea Health Technology R&D Project, Ministry of Health & Welfare, Republic of Korea (A111345).