Retraction to: Tumor Biol. (2014) 35:5869–5876

DOI 10.1007/s13277-014-1777-4

The above article has been retracted at the request of the authors, on the grounds of (1) inaccurate or non-validated data (which preclude the results from being replicated); (2) absence of acknowledgement of many participants, including some who should be listed as authors, and the role of the trial sponsor, Merck & Co., Inc.; and (3) one corresponding author not knowing that he was on the author list at the time of submission.