Though often considered to be an in vitro phenomenon, recent proof of principle trials using SPT therapy—two in men with CRPC and one in hormone sensitive PCa produced promising results, showing radiographic response rates of ~50% in men with CRPC, and favorable prostate specific antigen (PSA) responses in those with hormone naïve PCa [9,10,11]. The gene discussed is KLK3; the disease is posterior cortical atrophy.