With regard to the prostate-specific antigen (PSA, encoded by Kallikrein Related Peptidase 3 or KLK3), as commonly used blood serum biomarker in regular checkups for human PCa [21], no unambiguous canine ortholog has been identified for the human gene encoding PSA, i.e., KLK3 [22]. Here, KLK3 is linked to posterior cortical atrophy.