The Ad[I/PPT-E1A], a prostate-specific oncolytic adenovirus, has been engineered to have the E1A gene under the control of a recombinant regulatory sequence designated PPT that comprises a prostate specific antigen (PSA) enhancer, a prostate specific membrane antigen (PSMA) enhancer, and a T-cell receptor γ-chain alternate reading frame protein (TARP) promoter for the specific OV replication in prostate cancer cells, as previously described by Cheng et al. [53]. This evidence concerns the gene KLK3 and prostate cancer.