EVOLUTION Correction for “Biogeography of the Sulfolobus islandicus pan-genome,” by Michael L. Reno, Nicole L. Held, Christopher J. Fields, Patricia V. Burke, and Rachel J. Whitaker, which appeared in issue 21, May 26, 2009, of Proc Natl Acad Sci USA (106:8605–8610; first published May 12, 2009; 10.1073/pnas.0808945106).
The authors note that on page 8608, left column, the second sentence in the first full paragraph: “The majority of the lost genes have no matches to the National Center for Biotechnology Information (NCBI) nonredundant database” should instead have appeared as: “The majority of the lost genes have no matches to the National Center for Biotechnology Information (NCBI) nonredundant database outside of the Sulfolobales.” This error does not affect the conclusions of the article.