(Molecular Cell 58, 1053–1066; June 18, 2015) We, Richard S. Marshall and Richard D. Vierstra, recently identified an error in this 2015 Molecular Cell paper. In Figure 3C, a pair of confocal images (PAG1-GFP −N +ConA and RPN5a-GFP −N +ConA) were inadvertently duplicated within the figure, and a pair of confocal images (PAG1-GFP +N −ConA and RPN5a-GFP +N −ConA) were incorrectly duplicated from Figure 1C. These errors occurred when the same images were wrongly positioned as placeholders during figure preparation and were not correctly removed. The images were from Arabidopsis roots treated in the same way but were captured on different days and thus did not exactly match with those from other samples in the panel. We apologize for these errors and regret that they were not detected by us prior to publication. In the corrected version of Figure 3C shown below, all four duplicated images have been replaced with alternatives that were taken at the same time and with identical microscope settings as the others in Figure 3C.