KLK3 and prostate cancer: As a result of subgroup analysis by 1-PSA value, in patients with 4.0 ng/mL ≤ 1-PSA < 10.0 ng/mL, the incidence of prostate cancer was significantly higher in patients with elevated 2-PSA (groups i and ii) than in those with PSA falling below 4.0 ng/mL (group iv) (Supplementary Table S5).