There were some errors published in Development137, 3899-3910.

On p. 3900 and p. 3904, the references to Dai et al. (2002) were incorrect. The correct reference is Li et al. (2006).

Li, J., Chen, K., Zhu, L. and Pollard, J. W. (2006). Conditional deletion of the colony stimulating factor-1 receptor (c-fms proto-oncogene) in mice. Genesis44, 328-335.

On p. 3909, `We thank E. Aranda for the provision of Csflr–/– embryos.' was omitted from the acknowledgements.

The authors apologise to readers for this mistake.