There is an error in the print version of Development141, 1421.

In the piece ‘Measuring signal RAtio for limb patterning’, it should read: Miguel Torres and co-workers (p. 1534) now show that RA can inhibit distal identity in both chick and mouse. Distal inactivation of Meis1/2 is required for complete downregulation of RA signalling, hence permitting Hoxa13 expression to specify the autopod.

The online version has been corrected.

We apologise to the authors and readers for this mistake.