Reyes M, Lund T, Lenvik T, Aguiar D, Koodie L, Verfaillie CM. Purification and ex vivo expansion of postnatal human marrow mesodermal progenitor cells. Blood. 2001;98:2615-2625.

The authors wish to retract the November 1, 2001, article cited above. Based upon the conclusions of the investigation by the University of Minnesota and Blood, the paper was found to contain duplications and other irregularities in multiple figures. The authors extend their deepest apologies to the scientific community and to the readers, reviewers, and editors of Blood for publishing these data.