The present invention relates to oncogenes or tumor suppressor genes, as well as other genes, involved in prostate cancer and their expression products, as well as derivatives and analogs thereof. Provided are therapeutic compositions and methods of detecting and treating cancer, including prostate and other related cancers. Also provided are methods of diagnosing and/or prognosing prostate cancer by determining the expression level of at least one prostate cancer-cell-specific gene, including, for example, the ERG gene or the LTF gene alone, or in combination with at least one of the AMACR gene and the DD3 gene.