KLK3 and posterior cortical atrophy: On the other hand, the evidence suggests that rescreening men aged <65 years with PSA at baseline > 4.0 μg/L for active surveillance of low-grade disease may have a favorable risk-benefit balance if performed biennially [2], in particular considering: (a) the slow growth of PCa of any histological grade, and (b) the reference change value of ~20% useful to identify intraindividual PSA changes overtime significantly turning into clinically relevance [25,36,37].