Recently, Bussemakers et al. reported a novel prostate-specific gene, prostate cancer antigen 3 gene, also called DD3 (differential display code 3) which was found to be 10–100 fold over-expressed in 53 of 56 human prostate cancer samples in a Northern blot analysis whereas it was not expressed in adjacent non-malignant prostatic tissues[9]. This evidence concerns the gene PCA3 and Familial prostate cancer.