There was an error published in J. Cell Sci. 124, 1231-1244.

Jun San Huang and Shuan Shian Huang had an equity position in Auxagen Inc. during the time the research was carried out and should have declared that there is a conflict of interest.

Part of the research described in the article was supported by NIH grants awarded to St Louis University (AA 019233 to J.S.H.) and to Auxagen Inc. (HL 087463-01 and DK 078438 to J.S.H.).

The authors apologise for this omission.