Abstract
Following the publication of this paper, it was drawn to the Editor's attention by a concerned reader that the flow cytometric data shown in Fig. 2D on p. 1675 had already been submitted in different form in the following paper written by different authors at different research institutes: Tian R, Li Y and Gao M: Shikonin causes cell‑cycle arrest and induces apoptosis by regulating the EGFR‑NF‑κB signalling pathway in human epidermoid carcinoma A431 cells. Biosci Rep 28: e00189, 2015. After having conducted an independent review of the data in this figure in the Editorial Office, the concerns of the reader were found to be validated. Therefore, since the contentious data in the above article had already been submitted for publication prior to its submission to International Journal of Oncology, the Editor has decided that this paper should be retracted from the Journal. The authors were asked for an explanation to account for these concerns, but the Editorial Office did not receive any reply. The Editor apologizes to the readership for any inconvenience caused. [International Journal of Oncology 47: 1672‑1684, 2015; DOI: 10.3892/ijo.2015.3147].