VOLUME 281 (2006) PAGES 22062–22072
This article has been withdrawn by the authors. In June 2017, the Journal questioned whether there were duplications in Figs. 1E and 6C and questioned the absence of data in one field of Fig. 5B. The original data and originally submitted figures were not available for evaluation. The authors are not convinced there are any duplications in Figs. 1E and 6C. Regarding Fig. 5B, the authors agree that the data for “Vector” was inadvertently omitted from the final figure. The authors were able to locate replicate data performed at the time of the original work, which they state shows an absence of expression in the Vector panel. The authors offered to publish a correction based on this repeat experiment and, alternatively, offered to repeat the experiment. However, the Journal declined both these offers, a decision with which the authors disagree. The authors stand by the reproducibility of the experimental data and the conclusions of the paper. The paper, with confirmatory data supporting the results, can be obtained by contacting the authors.