KLK3 and cancer: Lowering the cut-off to 2.5 ng/mL, as suggested by some, would double the number of men defined as having abnormal levels while detecting cancers which may not become clinically significant, leading to overdiagnosis and overtreatment.35 Improving the ability of PSA to predict significant disease at values of ≤10.0 ng/mL is therefore warranted.