The present invention relates to the identification and use of gene expression profiles with clinical relevance to prostate cancer. In particular, the invention provides the identity of genes whose expression, at the transcriptional and protein levels, is correlated with prostate cancer progression. Methods and kits are described for using these gene expression profiles in the study and/or diagnosis of prostate cancer diseases, in the prediction of prostate cancer progression, and in the selection and/or monitoring of treatment regimens. The invention also relates to the screening of drugs that target these genes or their protein products, in particular for the development of therapeutics for modulating prostate cancer progression.