Correction to: Blood Cancer Journal (2015) 4, e271; doi:10.1038/bcj.2014.91; published online 2 January 2015
Since publication, the publishers have identified that this article was incorrectly placed in volume 4. The article belongs in volume 5.
The publishers would like to apologise for any inconvenience caused.
The article has been rectified and now carries the correct information.