Argonaute-2 regulates the proliferation of adult stem cells in planarian.

Correction to: Cell Research (2011) 21:1750–1754; doi:10.1038/cr.2011.151; published online 6 September 2011 In our discussion of the role of Argonaute proteins in stem cell regulation, we inadvertently omitted an important earlier contribution by Agata's group 1. Through testing conserved post-transcriptional regulators in the planarian Dugesia japonica, their study reports that Djago2 is required to maintain stem cell identity. We regret any inconvenience caused by this omission.