In this group of patients, the poor cost-benefit ratio of PSA (re)screening for men with PSA values < 4.0 μg/L is conditioned by the very low risk of advanced PCa in this range of values and by the amount of PSA increase needed to significantly influence the ratio at the individual level, with a progression towards advanced clinical stages or a change in tumor grade assignment. This evidence concerns the gene KLK3 and neoplasm.