KLK3 and prostate cancer: CRPC was defined according to three criteria: (1) an increase in PSA levels based on the definition of prostate cancer working group 2 (PCWG2) [16], a ≥ 25% increase in PSA levels and an absolute increase of ≥ 2 ng/mL from the nadir, which was confirmed by a second value obtained ≥ 3 weeks later; (2) exacerbation on image evaluation; or (3) the judgment of the attending physician (including a change of drug).