Nature Materials doi:10.1038/nmat2591; published online: 29 November 2009; corrected online: 13 January 2010.

In the version of this Article originally published, the following sentence in the caption of Fig. 5 should have been written as: “Images of negative control (b,c) and MD-mAb-functionalized cells subjected to 20 Hz–90 Oe a.c. fields for 10 min and TUNEL stained 4 h after the magnetic-field exposure (d,e)”

This has been corrected in all versions of this Article.