[Retracted] Metformin exerts anticancer effects through the inhibition of the Sonic hedgehog signaling pathway in breast cancer.

Following the publication of this paper, it was drawn to the Editor's attention by concerned readers that several of the cellular images shown in Figs. 6A and 8A, the scratch‑wound assay images shown in Fig. 5A, the western blotting data in Figs. 2C and 7A and the Matrigel invasion assays in Fig. 5C were strikingly similar to data appearing in different form in other articles by different authors. Owing to the fact that the contentious data in the above article had already been published elsewhere, or were already under consideration for publication, prior to its submission to , 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 a reply. The Editor apologizes to the readership for any inconvenience caused. [International Journal of Molecular Medicine 36: 204‑214, 2015; DOI: 10.3892/ijmm.2015.2217].