In Fernandes et al. (Nature Cell Biol.6, 1082−1093; 2004), one of the RT−PCR primers used for the twist mRNA analysis shown in Figs 1a and 4u was derived from an intronic sequence, and we have therefore repeated this analysis using exonic primers. The results obtained are essentially identical. The new primer sequences and conditions are: 5'-cgccccgctcctctgctctaccc-3', 5'-gccgccgccgccaccacctc-3', annealing temperature 65 °C, product length 352.
