Correction

COMMENTARY. For the article “The intestinal stem cell niche: There grows the neighborhood,” by Jason C. Mills and Jeffrey I. Gordon, which appeared in number 22, October 23, 2001, of Proc. Natl. Acad. Sci. USA (98, 12334–12336), the authors note the following. Due to a printer's error, on page 12334, in the fifth sentence of the fifth paragraph, the term “Swiss–Webster” mistakenly appeared. The sentence should have read “In SPASM, mice belonging to the inbred SWR strain are treated with N-nitroso-N-ethylurea (NEU) to induce mutations in a small percentage of intestinal stem cells or their immediate daughters.”