KLK3 and cancer: Current immunotherapeutic strategies against prostate cancer include administration of antibodies [7]–[9] and different kinds of cancer vaccines, for example administration of peptides derived from prostate antigen proteins [10], whole tumor cells [11], dendritic cells (DCs) loaded with peptides [12] or tumor cell lysates [13], and DNA encoding human Prostate Specific Antigen (PSA) [14].