Nature Cell Biol. 7, 311–318; 2005

The authors have added sequence information for the c-Myc siRNA probes used. This information is also available as Supplementary Information online.

The sequences of the c-Myc siRNAs from Ambion (Austin, TX) are as follows: sense, CGAUUCCUUCUAACAGAAAtt; antisense, UUUCUGUUAGAAGGAAUCGtt.

BLAST search analyses indicate that besides c-Myc, these sequences are also expressed by the human gene for lysophospholipase 1 (also called acyl protein thioesterase 1). This suggests that although specificity is high, it is not absolute. Because the additional target is a membrane protein and is not believed to be involved directly in gene expression, its potential knockdown is unlikely to contribute to the observed transcriptional responses.