After the important insights provided in preclinical studies [49] , the department of Oncology of the University Hospital of Uppsala is recruiting participants for a phase I/II trial, where intradermal EP (DERMA VAX) will be used as a delivery system. This study will assess the feasibility and safety of vaccination with increasing doses of xenogenic DNA coding for the Rhesus Prostate Specific Antigen (rhPSA), a protein that is 89% homologous to human PSA, administered in patients with relapsed prostate cancer.