Cassani B, Mirolo M, Cattaneo F, et al. Altered intracellular and extracellular signaling leads to impaired T-cell functions in ADA-SCID patients. Blood. 2008;111(8):4209-4219.

On page 4209 in the 15 April 2008 issue, there was an error in a clinical trial reference number, which reads “#NCT0059978.” The correct clinical trial reference number is “#NCT00599781.” The last sentence of the abstract should read, “The trials in this study are enrolled at www.clinicaltrials.gov as #NCT00598481 and #NCT00599781.”