KLK3 and pachyonychia congenita: In this cohort study of 43 298 patients with PC, among patients with a persistent PSA level but not those with an undetectable PSA level, a pre–radical prostatectomy (RP) PSA level greater than 20 ng/mL vs 20 ng/mL or less was significantly associated with reduced all-cause and PC-specific mortality risk, which can be explained by a higher proportion of patients with a pre-RP PSA level greater than 20 ng/mL vs 20 ng/mL or less who could have reached an undetectable PSA level if additional time for PSA assessment occurred before initiating post-RP therapy for a presumed persistent PSA.