Considering that the current screening diagnosis, based on serum PSA dosage and rectal examination, has a limited accuracy (mainly specificity) for differentiation of PCa from other prostatic diseases and considering the fragility of the results pointed out in this review, more studies with the aim of confirming (or excluding) MMPs and TIMPs as elective biomarkers for PCa should be welcomed, either for diagnosis, prognosis, or therapeutic referral. This evidence concerns the gene KLK3 and prostatitis.