GENETICS. For the article “Errα and Gabpa/b specify PGC-1α-dependent oxidative phosphorylation gene expression that is altered in diabetic muscle,” by Vamsi K. Mootha, Christoph Handschin, Dan Arlow, Xiaohui Xie, Julie St. Pierre, Smita Sihag, Wenli Yang, David Altshuler, Pere Puigserver, Nick Patterson, Patricia J. Willy, Ira G. Schulman, Richard A. Heyman, Eric S. Lander, and Bruce M. Spiegelman, which appeared in issue 17, April 27, 2004, of Proc. Natl. Acad. Sci. USA (101, 6570–6575; first published April 20, 2004; 10.1073/pnas. 0401401101), the authors note that “motifADE” and “motifs associated with differential expression” were interchanged in several instances. On page 6571, the last two sentences of the second paragraph in the left column, “Promoter databases and the motifs associated with differential expression (motifADE) source code. Complete results are available at www-genome.wi.mit.edu/mpg/PGC_motifs” should read: “Promoter databases, motifADE source code, and complete results are available at www.broad.mit.edu/mpg/PGC_motifs.” On page 6571, left column under Results, the subheading Discovering motifADE should read: Discovering Motifs Associated with Differential Expression. On page 6571, second paragraph, first sentence of the right column, “To overcome some of these obstacles, we devised a simple, nonparametric strategy for identifying motifADE (Fig. 1 A)” should read: “To overcome some of these obstacles, we devised a simple, nonparametric strategy for identifying motifs associated with differential expression (Fig. 1 A).”