Nat. Cell Biol. 13, 693–699 (2011); published online 22 May 2011; corrected after print 14 September 2011

In the version of this Letter initially published online and in print, an article by Lizé et al. (Cell Cycle 9, 4579–4583; 2010), which reports that miR-449 microRNAs accumulate during mucociliary differentiation of human airway epithelia, was inadvertently omitted from the references list. On pages 1–2, the following text has replaced the previous text: “miR-449a, miR-449b and miR-449c (collectively named miR-449), constitute by far the most strongly induced microRNAs during epithelium differentiation in both species. Although representing less than 0.01% of all microRNA sequences in proliferating HAECs, miR-449 accounted for more than 8% of the microRNA reads in differentiated HAECs (Fig. 1a and Supplementary Fig. S1c,d; see also ref. 13).”

The omitted reference has now been added to the reference list:

13. Lizé, M., Herr, C., Klimke, A., Bals, R. & Dobbelstein, M. MicroRNA 449a levels increase by several orders of magnitude during mucociliary differentiation of airway epithelia. Cell Cycle 9, 4579–4583 (2010).

References 13–40 have been changed to 14–41, respectively.