Following the publication of this paper, the Journal was alerted by an investigation committee of Niigata University to the fact that the paper had been identified as a duplicate publication, which had already been published. Therefore, in accordance with the rules of Niigata University Fraud Investigation committee, a request was made that the paper be retracted. After having been in contact with the authors, they agreed with the decision to retract the paper. The Editor apologizes to the readership for any inconvenience caused. [the original article was published in International Journal of Oncology 38: 1227-1236, 2011; DOI: 10.3892/ijo.2011.959].
Keywords: cholangiocarcinoma; extrahepatic bile duct carcinoma; immunofluorescence; p53-binding protein 1; prognosis.