A functional analysis demonstrated that the expression of certain proteinases such as dipeptidyl peptidase 4 (DPP4), carboxypeptidase E (CPE) and prostate specific antigen (KLK3), were significantly altered in both primary aggressive PCa and metastatic tumors compared to primary NAG PCa and normal prostate tissues. This evidence concerns the gene KLK3 and metastatic neoplasm.