Expression of Concern: Betulinic Acid: A New Cytotoxic Agent Against Malignant Brain-tumor Cells

Expression of Concern: S. Fulda, I. Jeremias, H. H. Steiner, T. Pietsch, and K.-M. Debatin, “ Betulinic Acid: A New Cytotoxic Agent Against Malignant Brain-tumor Cells,” International Journal of Cancer 82, no. 3 (1999): 435–441, https://doi.org/10.1002/(SICI)1097-0215(19990730)82:3<435::AID-IJC18>3.0.CO;2-1.

This expression of concern is for the above article, published online on 10 November 1999 in Wiley Online Library (wileyonlinelibrary.com), and was agreed between the authors; the journal Editor-in-Chief, Christoph Plass; the Union for International Cancer Control-UICC; and John Wiley & Sons Ltd.

The Expression of Concern was agreed due to concerns by third parties on the data presented in the article. Specifically, a potential duplication of Western Blot bands depicting casp-3 in Figure 4a (#1–5 in the left panel and #1–5 in the right panel) has been detected.

The authors are unable to retrieve the original raw data underlying these experiments due to the time (25 years) elapsed since publication, in line with the regulations of the German Research Foundation, and state that they cannot rule out an unintentional error in the preparation of the figure, misplacement of blots or technical artefacts. The authors state that the concern raised does not affect the results and conclusions of the article. As these issues cannot be definitively resolved, the journal is publishing this Expression of Concern to inform and alert the readers.