Correction to: NPG Asia Materials;

https://doi.org/10.1038/s41427-018-0015-8

published online 03 April 2018

After online publication of this article, the authors noticed an error of Fig. 3h in Fig. 3. The correct Fig. 3 of this article should have read as below.

figure 1

Fig. 3

The authors apologize for any inconvenience caused.