The publisher of Expert Opinion on Investigational Drugsand authors have retracted the following article:Diletta Bianchini, Andrea Zivi, Shahneen Sandhu, Johann S de BonoExpert Opinion on Investigational Drugs December 2010, Vol. 19, No. 12: 1487-1502.Upon investigation, it was found that the article constitutes a case of redundant publication, due to its similarity to a paper previously published in Annals of Oncology(‘Horizon scanning for novel therapeutics for the treatment of prostate cancer’, D Bianchini, A Zivi, S Sandhu and JS de Bono), Ann Oncol. 2010 Oct; 21 Suppl 7:vii43-55.We would like to state that this situation was due to an honest error, and the authors are happy for the article to be retracted and would like to apologise for any inconvenience this causes to readers.