The 4Kscore represents a serum-based biomarker that associates multiple factors: age, digital rectal examination aspect, results of previous prostate biopsies, measurements of tPSA, free PSA, intact PSA, which is a form of free PSA, and human kallikrein 2 (hK2) that has promising results in PCa detection. This evidence concerns the gene KLK3 and posterior cortical atrophy.