In the article “Kalirin-7 Is Required for Synaptic Structure and Function” by Xin-Ming Ma, Drew D. Kiraly, Eric D. Gaier, Yanping Wang, Eun-Ji Kim, Eric S. Levine, Betty A. Eipper, and Richard E. Mains, which appeared on pages 12368–12382 of the November 19, 2008 issue, the authors regret that the same magnified image of wild-type hippocampus appeared in Panel C (wild-type) and Panel F (improperly labeled knock-out) of Supplemental Figure 2. The correct image of knock-out hippocampus has been inserted in Panel F of the revised figure and is listed below.