The Editors-in-Chief would like to alert the readers that concerns have been raised regarding highly similar caspase-8 blots in Figs. 1c and 2c in this article. As over 18 years have passed since the publication of this article, the original raw data are no longer available, in accordance with German regulations. As such, the authors have been unable to conclusively address this issue.

The authors have stated that the TSA treatment shown in Figs. 1c and 2c functions as a repetitive positive control, and the conclusions of the article are not affected by this concern.

Both authors agree to this Editorial Expression of Concern.