KLK3 and cancer: Secondly, random sampling reveals clinically insignificant cancers (ciPCa), most frequently defined by the ‘Epstein’ criteria (Gleason Score 6 [3 + 3], less than 3 cores with cancer involvement, no core with cancer involvement ≥ 50% and a prostate-specific-antigen-density of < 0.15 ng/ml2), which are unlikely to cause any symptoms in the patient’s lifetime, but might contribute to subsequent overtreatment once being diagnosed [4].