Correction to: Nature Communications, published online 10 May 2018

The original version of this Article omitted a declaration from the competing interests statement, which should have included the following: ‘One of the authors, Y.L., is an editor on the staff of Nature Communications, but was not in any way involved in the journal review process. The other authors declare no competing interests’. This has now been corrected in both the PDF and HTML versions of the Article.