Nat. Med. 8, 681–686 (2002)

The reported antisense strand of the CD19 siRNA used as a negative control in Figure 3 (p. 683), with the sequence 5′-GAAUCAUCCUCCGUCCGGGGU-3′, did not have the appropriate sequence. The CD19 RNA used in Figure 3 is therefore not relevant as an unrelated siRNA control. Additional experiments using other control siRNAs confirmed that the silencing phenomenon reported in Figure 3 is specific; the conclusions of the paper remain unchanged. The authors regret the error.