Alford and co-workers overviewed the several tests available on the market for PCa screening developed for different patient specimens, including (i) Blood: Prostate Health Index (PHI), 4k-score (4-kallikrein panel) and Apifiny; (ii) Urine: SelectMDx, PCA3, Michigan Prostate Score (MiPS); (iii) Biopsy: ConfirmMDx, Oncotype Dx, ProMark, PTEN/TMPRSS2:ERG, Prolaris, Decipher [8]. This evidence concerns the gene KLK4 and posterior cortical atrophy.