Kenkichi Takahashi, Naokado Ikeda, Naosuke Nonoguchi, Yoshinaga Kajimoto, Shin-Ichi Miyatake, Yuichiro Hagiya, Shun-Ichiro Ogura, Hiroshi Nakagawa, Toshihisa Ishikawa, and Toshihiko Kuroiwa Neuro-Oncology 13(11):1234-1243. http://neuro-oncology.oxfordjournals.org/content/13/11/1234.
Corresponding Author: Naokado Ikeda, MD, PhD, Department of Neurosurgery, Osaka Medical College, 2–7 Daigaku-machi, Takatsuki, Osaka 569-8686, Japan (neu094@poh.osaka-med.ac.jp)
Neuro-oncology regrets to inform readers that this article has been retracted at the authors' request.
The authors have recently identified technical but fundamental errors in the preparation of the standard curve of quantitative real time PCR (qRT-PCR).
As the consequence, the experimental results presented in the paper are wrong with respect to mRNA expression levels, in particular those presented in Figures 3 and 4. The authors have investigated the technical mistake by examining all the data recorded in laboratory books and a laboratory computer as well as by newly performing western blot analysis for the CPOX protein in surgically resected samples from malignant glioma patients. The subsequent investigation shows that CPOX expression level is not a key factor for 5-ALA-induced fluorescence in malignant brain tumors. The authors sincerely apologize for the technical mistakes made in their study.