The article “Requirement for Protein Synthesis at Developing Synapses” by Joseph Sebeo, Kuangfu Hsiao, Ozlem Bozdagi, Dani Dumitriu, Yongchao Ge, Qiang Zhou, and Deanna L. Benson, which appeared on pages 9778–9793 of the August 5, 2009 issue has been retracted by the authors, who report the following: “It has come to our attention that there were serious irregularities with some of the Western blots in the paper. All authors concur the paper should be retracted to avoid misleading readers and investigators in the field, but we would like to emphasize that the primary effects of protein synthesis blockers on synapses that were described are not in question and will be submitted for publication at a future date. We apologize for any inconvenience or misunderstanding that this may have caused our colleagues.”