Correction to: Gene Therapy (2013) 20, 1124–1130; doi:10.1038/gt.2013.38; published online 25 July 2013

Since the online publication of this article the authors have noticed that the wrong grant number was included. The first line of the Acknowledgements should read:

This work was supported by the Telethon grant GGP04039, and from MIUR, project PRIN protocol number 2004069479_004.

The corrected article appears in this issue, and the html and PDF versions online have also been amended.

The authors would like to apologize for this error.