The 4Kscore® is a prebiopsy blood test developed by OPKOlab that incorporates a panel of four kallikreins (tPSA, fPSA, intact PSA [iPSA] and human kallikrein 2 [hK2]) combined with clinical features such as the 4Kscore®, which determines a man’s risk for high-grade aggressive PCa (GS ≥ 7) [36], improving decision making regarding prostate biopsy. Here, KLK3 is linked to posterior cortical atrophy.