Vol. 170, No. 6, September 12, 2005. Pages 913–924.

Authors and their means of support were not listed fully in the acknowledgement section. The clarified paragraph appears below.

This research was supported by a grant from the Canadian Institute of Health Research (CIHR) to N. Sonenberg and by U.S. Public Health Service (PHS) grants GM38277 and GM55407 to D.R. Schoenberg. M.A. Ferraiuolo was supported by Doctoral studentships awarded from Fonds de la Recherche en Santé du Québec (FRSQ) and McGill Faculty of Medicine. E.L. Murray was supported by PHS grant T32 CA09338. N. Sonenberg is a CIHR distinguished scientist and a Howard Hughes Medical Institute International Scholar.