Resumen: This article addresses the identification of maize transcription start sites (TSSs) by CAGE in the sequenced maize B73 inbred. To see how variable TSSs might be across genotypes, we also performed CAGE in what we believed at the time to be the Mo17 genotype. Because the Mo17 genome was not available at the time, we mapped all reads to the B73 genome. In more recent studies, we have fully sequenced the genome of this putative Mo17, and it has now become clear that what we thought was Mo17 is actually maize inbred line A632. We believe the confusion arose from a mistake in labeling of the seed. Therefore, in this article, every instance of "Mo17"actually refers to maize inbred line A632. The findings and conclusions in the article are unaffected by this mistake: we originally picked Mo17 arbitrarily (as it is a widely used inbred line), and everything was mapped back to B73-hence we could have used any inbred line. However, for those that may wish to use the CAGE data that we generated and map it to the now-accessible Mo17 genome, it is important to know that we used A632 and not Mo17. All authors are in agreement with this correction. We sincerely apologize for the mistake and any inconvenience caused. Editors' note: This correction was reviewed by members of The Plant Cell editorial board. The authors are responsible for providing a complete listing and accurate explanations for all known errors or instances of inappropriate data handling or image manipulation associated with the original publication.